0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8(10) to 64 bit double precision IEEE 754 binary floating point representation standard (1 bit for sign, 11 bits for exponent, 52 bits for mantissa)

What are the steps to convert decimal number
0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8(10) to 64 bit double precision IEEE 754 binary floating point representation (1 bit for sign, 11 bits for exponent, 52 bits for mantissa)

1. First, convert to binary (in base 2) the integer part: 0.
Divide the number repeatedly by 2.

Keep track of each remainder.

We stop when we get a quotient that is equal to zero.


  • division = quotient + remainder;
  • 0 ÷ 2 = 0 + 0;

2. Construct the base 2 representation of the integer part of the number.

Take all the remainders starting from the bottom of the list constructed above.

0(10) =


0(2)


3. Convert to binary (base 2) the fractional part: 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8.

Multiply it repeatedly by 2.


Keep track of each integer part of the results.


Stop when we get a fractional part that is equal to zero.


  • #) multiplying = integer + fractional part;
  • 1) 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8 × 2 = 0 + 0.000 000 000 007 269 999 999 999 999 516 522 114 064 601 356 670 305 975 6;
  • 2) 0.000 000 000 007 269 999 999 999 999 516 522 114 064 601 356 670 305 975 6 × 2 = 0 + 0.000 000 000 014 539 999 999 999 999 033 044 228 129 202 713 340 611 951 2;
  • 3) 0.000 000 000 014 539 999 999 999 999 033 044 228 129 202 713 340 611 951 2 × 2 = 0 + 0.000 000 000 029 079 999 999 999 998 066 088 456 258 405 426 681 223 902 4;
  • 4) 0.000 000 000 029 079 999 999 999 998 066 088 456 258 405 426 681 223 902 4 × 2 = 0 + 0.000 000 000 058 159 999 999 999 996 132 176 912 516 810 853 362 447 804 8;
  • 5) 0.000 000 000 058 159 999 999 999 996 132 176 912 516 810 853 362 447 804 8 × 2 = 0 + 0.000 000 000 116 319 999 999 999 992 264 353 825 033 621 706 724 895 609 6;
  • 6) 0.000 000 000 116 319 999 999 999 992 264 353 825 033 621 706 724 895 609 6 × 2 = 0 + 0.000 000 000 232 639 999 999 999 984 528 707 650 067 243 413 449 791 219 2;
  • 7) 0.000 000 000 232 639 999 999 999 984 528 707 650 067 243 413 449 791 219 2 × 2 = 0 + 0.000 000 000 465 279 999 999 999 969 057 415 300 134 486 826 899 582 438 4;
  • 8) 0.000 000 000 465 279 999 999 999 969 057 415 300 134 486 826 899 582 438 4 × 2 = 0 + 0.000 000 000 930 559 999 999 999 938 114 830 600 268 973 653 799 164 876 8;
  • 9) 0.000 000 000 930 559 999 999 999 938 114 830 600 268 973 653 799 164 876 8 × 2 = 0 + 0.000 000 001 861 119 999 999 999 876 229 661 200 537 947 307 598 329 753 6;
  • 10) 0.000 000 001 861 119 999 999 999 876 229 661 200 537 947 307 598 329 753 6 × 2 = 0 + 0.000 000 003 722 239 999 999 999 752 459 322 401 075 894 615 196 659 507 2;
  • 11) 0.000 000 003 722 239 999 999 999 752 459 322 401 075 894 615 196 659 507 2 × 2 = 0 + 0.000 000 007 444 479 999 999 999 504 918 644 802 151 789 230 393 319 014 4;
  • 12) 0.000 000 007 444 479 999 999 999 504 918 644 802 151 789 230 393 319 014 4 × 2 = 0 + 0.000 000 014 888 959 999 999 999 009 837 289 604 303 578 460 786 638 028 8;
  • 13) 0.000 000 014 888 959 999 999 999 009 837 289 604 303 578 460 786 638 028 8 × 2 = 0 + 0.000 000 029 777 919 999 999 998 019 674 579 208 607 156 921 573 276 057 6;
  • 14) 0.000 000 029 777 919 999 999 998 019 674 579 208 607 156 921 573 276 057 6 × 2 = 0 + 0.000 000 059 555 839 999 999 996 039 349 158 417 214 313 843 146 552 115 2;
  • 15) 0.000 000 059 555 839 999 999 996 039 349 158 417 214 313 843 146 552 115 2 × 2 = 0 + 0.000 000 119 111 679 999 999 992 078 698 316 834 428 627 686 293 104 230 4;
  • 16) 0.000 000 119 111 679 999 999 992 078 698 316 834 428 627 686 293 104 230 4 × 2 = 0 + 0.000 000 238 223 359 999 999 984 157 396 633 668 857 255 372 586 208 460 8;
  • 17) 0.000 000 238 223 359 999 999 984 157 396 633 668 857 255 372 586 208 460 8 × 2 = 0 + 0.000 000 476 446 719 999 999 968 314 793 267 337 714 510 745 172 416 921 6;
  • 18) 0.000 000 476 446 719 999 999 968 314 793 267 337 714 510 745 172 416 921 6 × 2 = 0 + 0.000 000 952 893 439 999 999 936 629 586 534 675 429 021 490 344 833 843 2;
  • 19) 0.000 000 952 893 439 999 999 936 629 586 534 675 429 021 490 344 833 843 2 × 2 = 0 + 0.000 001 905 786 879 999 999 873 259 173 069 350 858 042 980 689 667 686 4;
  • 20) 0.000 001 905 786 879 999 999 873 259 173 069 350 858 042 980 689 667 686 4 × 2 = 0 + 0.000 003 811 573 759 999 999 746 518 346 138 701 716 085 961 379 335 372 8;
  • 21) 0.000 003 811 573 759 999 999 746 518 346 138 701 716 085 961 379 335 372 8 × 2 = 0 + 0.000 007 623 147 519 999 999 493 036 692 277 403 432 171 922 758 670 745 6;
  • 22) 0.000 007 623 147 519 999 999 493 036 692 277 403 432 171 922 758 670 745 6 × 2 = 0 + 0.000 015 246 295 039 999 998 986 073 384 554 806 864 343 845 517 341 491 2;
  • 23) 0.000 015 246 295 039 999 998 986 073 384 554 806 864 343 845 517 341 491 2 × 2 = 0 + 0.000 030 492 590 079 999 997 972 146 769 109 613 728 687 691 034 682 982 4;
  • 24) 0.000 030 492 590 079 999 997 972 146 769 109 613 728 687 691 034 682 982 4 × 2 = 0 + 0.000 060 985 180 159 999 995 944 293 538 219 227 457 375 382 069 365 964 8;
  • 25) 0.000 060 985 180 159 999 995 944 293 538 219 227 457 375 382 069 365 964 8 × 2 = 0 + 0.000 121 970 360 319 999 991 888 587 076 438 454 914 750 764 138 731 929 6;
  • 26) 0.000 121 970 360 319 999 991 888 587 076 438 454 914 750 764 138 731 929 6 × 2 = 0 + 0.000 243 940 720 639 999 983 777 174 152 876 909 829 501 528 277 463 859 2;
  • 27) 0.000 243 940 720 639 999 983 777 174 152 876 909 829 501 528 277 463 859 2 × 2 = 0 + 0.000 487 881 441 279 999 967 554 348 305 753 819 659 003 056 554 927 718 4;
  • 28) 0.000 487 881 441 279 999 967 554 348 305 753 819 659 003 056 554 927 718 4 × 2 = 0 + 0.000 975 762 882 559 999 935 108 696 611 507 639 318 006 113 109 855 436 8;
  • 29) 0.000 975 762 882 559 999 935 108 696 611 507 639 318 006 113 109 855 436 8 × 2 = 0 + 0.001 951 525 765 119 999 870 217 393 223 015 278 636 012 226 219 710 873 6;
  • 30) 0.001 951 525 765 119 999 870 217 393 223 015 278 636 012 226 219 710 873 6 × 2 = 0 + 0.003 903 051 530 239 999 740 434 786 446 030 557 272 024 452 439 421 747 2;
  • 31) 0.003 903 051 530 239 999 740 434 786 446 030 557 272 024 452 439 421 747 2 × 2 = 0 + 0.007 806 103 060 479 999 480 869 572 892 061 114 544 048 904 878 843 494 4;
  • 32) 0.007 806 103 060 479 999 480 869 572 892 061 114 544 048 904 878 843 494 4 × 2 = 0 + 0.015 612 206 120 959 998 961 739 145 784 122 229 088 097 809 757 686 988 8;
  • 33) 0.015 612 206 120 959 998 961 739 145 784 122 229 088 097 809 757 686 988 8 × 2 = 0 + 0.031 224 412 241 919 997 923 478 291 568 244 458 176 195 619 515 373 977 6;
  • 34) 0.031 224 412 241 919 997 923 478 291 568 244 458 176 195 619 515 373 977 6 × 2 = 0 + 0.062 448 824 483 839 995 846 956 583 136 488 916 352 391 239 030 747 955 2;
  • 35) 0.062 448 824 483 839 995 846 956 583 136 488 916 352 391 239 030 747 955 2 × 2 = 0 + 0.124 897 648 967 679 991 693 913 166 272 977 832 704 782 478 061 495 910 4;
  • 36) 0.124 897 648 967 679 991 693 913 166 272 977 832 704 782 478 061 495 910 4 × 2 = 0 + 0.249 795 297 935 359 983 387 826 332 545 955 665 409 564 956 122 991 820 8;
  • 37) 0.249 795 297 935 359 983 387 826 332 545 955 665 409 564 956 122 991 820 8 × 2 = 0 + 0.499 590 595 870 719 966 775 652 665 091 911 330 819 129 912 245 983 641 6;
  • 38) 0.499 590 595 870 719 966 775 652 665 091 911 330 819 129 912 245 983 641 6 × 2 = 0 + 0.999 181 191 741 439 933 551 305 330 183 822 661 638 259 824 491 967 283 2;
  • 39) 0.999 181 191 741 439 933 551 305 330 183 822 661 638 259 824 491 967 283 2 × 2 = 1 + 0.998 362 383 482 879 867 102 610 660 367 645 323 276 519 648 983 934 566 4;
  • 40) 0.998 362 383 482 879 867 102 610 660 367 645 323 276 519 648 983 934 566 4 × 2 = 1 + 0.996 724 766 965 759 734 205 221 320 735 290 646 553 039 297 967 869 132 8;
  • 41) 0.996 724 766 965 759 734 205 221 320 735 290 646 553 039 297 967 869 132 8 × 2 = 1 + 0.993 449 533 931 519 468 410 442 641 470 581 293 106 078 595 935 738 265 6;
  • 42) 0.993 449 533 931 519 468 410 442 641 470 581 293 106 078 595 935 738 265 6 × 2 = 1 + 0.986 899 067 863 038 936 820 885 282 941 162 586 212 157 191 871 476 531 2;
  • 43) 0.986 899 067 863 038 936 820 885 282 941 162 586 212 157 191 871 476 531 2 × 2 = 1 + 0.973 798 135 726 077 873 641 770 565 882 325 172 424 314 383 742 953 062 4;
  • 44) 0.973 798 135 726 077 873 641 770 565 882 325 172 424 314 383 742 953 062 4 × 2 = 1 + 0.947 596 271 452 155 747 283 541 131 764 650 344 848 628 767 485 906 124 8;
  • 45) 0.947 596 271 452 155 747 283 541 131 764 650 344 848 628 767 485 906 124 8 × 2 = 1 + 0.895 192 542 904 311 494 567 082 263 529 300 689 697 257 534 971 812 249 6;
  • 46) 0.895 192 542 904 311 494 567 082 263 529 300 689 697 257 534 971 812 249 6 × 2 = 1 + 0.790 385 085 808 622 989 134 164 527 058 601 379 394 515 069 943 624 499 2;
  • 47) 0.790 385 085 808 622 989 134 164 527 058 601 379 394 515 069 943 624 499 2 × 2 = 1 + 0.580 770 171 617 245 978 268 329 054 117 202 758 789 030 139 887 248 998 4;
  • 48) 0.580 770 171 617 245 978 268 329 054 117 202 758 789 030 139 887 248 998 4 × 2 = 1 + 0.161 540 343 234 491 956 536 658 108 234 405 517 578 060 279 774 497 996 8;
  • 49) 0.161 540 343 234 491 956 536 658 108 234 405 517 578 060 279 774 497 996 8 × 2 = 0 + 0.323 080 686 468 983 913 073 316 216 468 811 035 156 120 559 548 995 993 6;
  • 50) 0.323 080 686 468 983 913 073 316 216 468 811 035 156 120 559 548 995 993 6 × 2 = 0 + 0.646 161 372 937 967 826 146 632 432 937 622 070 312 241 119 097 991 987 2;
  • 51) 0.646 161 372 937 967 826 146 632 432 937 622 070 312 241 119 097 991 987 2 × 2 = 1 + 0.292 322 745 875 935 652 293 264 865 875 244 140 624 482 238 195 983 974 4;
  • 52) 0.292 322 745 875 935 652 293 264 865 875 244 140 624 482 238 195 983 974 4 × 2 = 0 + 0.584 645 491 751 871 304 586 529 731 750 488 281 248 964 476 391 967 948 8;
  • 53) 0.584 645 491 751 871 304 586 529 731 750 488 281 248 964 476 391 967 948 8 × 2 = 1 + 0.169 290 983 503 742 609 173 059 463 500 976 562 497 928 952 783 935 897 6;
  • 54) 0.169 290 983 503 742 609 173 059 463 500 976 562 497 928 952 783 935 897 6 × 2 = 0 + 0.338 581 967 007 485 218 346 118 927 001 953 124 995 857 905 567 871 795 2;
  • 55) 0.338 581 967 007 485 218 346 118 927 001 953 124 995 857 905 567 871 795 2 × 2 = 0 + 0.677 163 934 014 970 436 692 237 854 003 906 249 991 715 811 135 743 590 4;
  • 56) 0.677 163 934 014 970 436 692 237 854 003 906 249 991 715 811 135 743 590 4 × 2 = 1 + 0.354 327 868 029 940 873 384 475 708 007 812 499 983 431 622 271 487 180 8;
  • 57) 0.354 327 868 029 940 873 384 475 708 007 812 499 983 431 622 271 487 180 8 × 2 = 0 + 0.708 655 736 059 881 746 768 951 416 015 624 999 966 863 244 542 974 361 6;
  • 58) 0.708 655 736 059 881 746 768 951 416 015 624 999 966 863 244 542 974 361 6 × 2 = 1 + 0.417 311 472 119 763 493 537 902 832 031 249 999 933 726 489 085 948 723 2;
  • 59) 0.417 311 472 119 763 493 537 902 832 031 249 999 933 726 489 085 948 723 2 × 2 = 0 + 0.834 622 944 239 526 987 075 805 664 062 499 999 867 452 978 171 897 446 4;
  • 60) 0.834 622 944 239 526 987 075 805 664 062 499 999 867 452 978 171 897 446 4 × 2 = 1 + 0.669 245 888 479 053 974 151 611 328 124 999 999 734 905 956 343 794 892 8;
  • 61) 0.669 245 888 479 053 974 151 611 328 124 999 999 734 905 956 343 794 892 8 × 2 = 1 + 0.338 491 776 958 107 948 303 222 656 249 999 999 469 811 912 687 589 785 6;
  • 62) 0.338 491 776 958 107 948 303 222 656 249 999 999 469 811 912 687 589 785 6 × 2 = 0 + 0.676 983 553 916 215 896 606 445 312 499 999 998 939 623 825 375 179 571 2;
  • 63) 0.676 983 553 916 215 896 606 445 312 499 999 998 939 623 825 375 179 571 2 × 2 = 1 + 0.353 967 107 832 431 793 212 890 624 999 999 997 879 247 650 750 359 142 4;
  • 64) 0.353 967 107 832 431 793 212 890 624 999 999 997 879 247 650 750 359 142 4 × 2 = 0 + 0.707 934 215 664 863 586 425 781 249 999 999 995 758 495 301 500 718 284 8;
  • 65) 0.707 934 215 664 863 586 425 781 249 999 999 995 758 495 301 500 718 284 8 × 2 = 1 + 0.415 868 431 329 727 172 851 562 499 999 999 991 516 990 603 001 436 569 6;
  • 66) 0.415 868 431 329 727 172 851 562 499 999 999 991 516 990 603 001 436 569 6 × 2 = 0 + 0.831 736 862 659 454 345 703 124 999 999 999 983 033 981 206 002 873 139 2;
  • 67) 0.831 736 862 659 454 345 703 124 999 999 999 983 033 981 206 002 873 139 2 × 2 = 1 + 0.663 473 725 318 908 691 406 249 999 999 999 966 067 962 412 005 746 278 4;
  • 68) 0.663 473 725 318 908 691 406 249 999 999 999 966 067 962 412 005 746 278 4 × 2 = 1 + 0.326 947 450 637 817 382 812 499 999 999 999 932 135 924 824 011 492 556 8;
  • 69) 0.326 947 450 637 817 382 812 499 999 999 999 932 135 924 824 011 492 556 8 × 2 = 0 + 0.653 894 901 275 634 765 624 999 999 999 999 864 271 849 648 022 985 113 6;
  • 70) 0.653 894 901 275 634 765 624 999 999 999 999 864 271 849 648 022 985 113 6 × 2 = 1 + 0.307 789 802 551 269 531 249 999 999 999 999 728 543 699 296 045 970 227 2;
  • 71) 0.307 789 802 551 269 531 249 999 999 999 999 728 543 699 296 045 970 227 2 × 2 = 0 + 0.615 579 605 102 539 062 499 999 999 999 999 457 087 398 592 091 940 454 4;
  • 72) 0.615 579 605 102 539 062 499 999 999 999 999 457 087 398 592 091 940 454 4 × 2 = 1 + 0.231 159 210 205 078 124 999 999 999 999 998 914 174 797 184 183 880 908 8;
  • 73) 0.231 159 210 205 078 124 999 999 999 999 998 914 174 797 184 183 880 908 8 × 2 = 0 + 0.462 318 420 410 156 249 999 999 999 999 997 828 349 594 368 367 761 817 6;
  • 74) 0.462 318 420 410 156 249 999 999 999 999 997 828 349 594 368 367 761 817 6 × 2 = 0 + 0.924 636 840 820 312 499 999 999 999 999 995 656 699 188 736 735 523 635 2;
  • 75) 0.924 636 840 820 312 499 999 999 999 999 995 656 699 188 736 735 523 635 2 × 2 = 1 + 0.849 273 681 640 624 999 999 999 999 999 991 313 398 377 473 471 047 270 4;
  • 76) 0.849 273 681 640 624 999 999 999 999 999 991 313 398 377 473 471 047 270 4 × 2 = 1 + 0.698 547 363 281 249 999 999 999 999 999 982 626 796 754 946 942 094 540 8;
  • 77) 0.698 547 363 281 249 999 999 999 999 999 982 626 796 754 946 942 094 540 8 × 2 = 1 + 0.397 094 726 562 499 999 999 999 999 999 965 253 593 509 893 884 189 081 6;
  • 78) 0.397 094 726 562 499 999 999 999 999 999 965 253 593 509 893 884 189 081 6 × 2 = 0 + 0.794 189 453 124 999 999 999 999 999 999 930 507 187 019 787 768 378 163 2;
  • 79) 0.794 189 453 124 999 999 999 999 999 999 930 507 187 019 787 768 378 163 2 × 2 = 1 + 0.588 378 906 249 999 999 999 999 999 999 861 014 374 039 575 536 756 326 4;
  • 80) 0.588 378 906 249 999 999 999 999 999 999 861 014 374 039 575 536 756 326 4 × 2 = 1 + 0.176 757 812 499 999 999 999 999 999 999 722 028 748 079 151 073 512 652 8;
  • 81) 0.176 757 812 499 999 999 999 999 999 999 722 028 748 079 151 073 512 652 8 × 2 = 0 + 0.353 515 624 999 999 999 999 999 999 999 444 057 496 158 302 147 025 305 6;
  • 82) 0.353 515 624 999 999 999 999 999 999 999 444 057 496 158 302 147 025 305 6 × 2 = 0 + 0.707 031 249 999 999 999 999 999 999 998 888 114 992 316 604 294 050 611 2;
  • 83) 0.707 031 249 999 999 999 999 999 999 998 888 114 992 316 604 294 050 611 2 × 2 = 1 + 0.414 062 499 999 999 999 999 999 999 997 776 229 984 633 208 588 101 222 4;
  • 84) 0.414 062 499 999 999 999 999 999 999 997 776 229 984 633 208 588 101 222 4 × 2 = 0 + 0.828 124 999 999 999 999 999 999 999 995 552 459 969 266 417 176 202 444 8;
  • 85) 0.828 124 999 999 999 999 999 999 999 995 552 459 969 266 417 176 202 444 8 × 2 = 1 + 0.656 249 999 999 999 999 999 999 999 991 104 919 938 532 834 352 404 889 6;
  • 86) 0.656 249 999 999 999 999 999 999 999 991 104 919 938 532 834 352 404 889 6 × 2 = 1 + 0.312 499 999 999 999 999 999 999 999 982 209 839 877 065 668 704 809 779 2;
  • 87) 0.312 499 999 999 999 999 999 999 999 982 209 839 877 065 668 704 809 779 2 × 2 = 0 + 0.624 999 999 999 999 999 999 999 999 964 419 679 754 131 337 409 619 558 4;
  • 88) 0.624 999 999 999 999 999 999 999 999 964 419 679 754 131 337 409 619 558 4 × 2 = 1 + 0.249 999 999 999 999 999 999 999 999 928 839 359 508 262 674 819 239 116 8;
  • 89) 0.249 999 999 999 999 999 999 999 999 928 839 359 508 262 674 819 239 116 8 × 2 = 0 + 0.499 999 999 999 999 999 999 999 999 857 678 719 016 525 349 638 478 233 6;
  • 90) 0.499 999 999 999 999 999 999 999 999 857 678 719 016 525 349 638 478 233 6 × 2 = 0 + 0.999 999 999 999 999 999 999 999 999 715 357 438 033 050 699 276 956 467 2;
  • 91) 0.999 999 999 999 999 999 999 999 999 715 357 438 033 050 699 276 956 467 2 × 2 = 1 + 0.999 999 999 999 999 999 999 999 999 430 714 876 066 101 398 553 912 934 4;

We didn't get any fractional part that was equal to zero. But we had enough iterations (over Mantissa limit) and at least one integer that was different from zero => FULL STOP (Losing precision - the converted number we get in the end will be just a very good approximation of the initial one).


4. Construct the base 2 representation of the fractional part of the number.

Take all the integer parts of the multiplying operations, starting from the top of the constructed list above:


0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2)

5. Positive number before normalization:

0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2)

6. Normalize the binary representation of the number.

Shift the decimal mark 39 positions to the right, so that only one non zero digit remains to the left of it:


0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2) × 20 =


1.1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001(2) × 2-39


7. Up to this moment, there are the following elements that would feed into the 64 bit double precision IEEE 754 binary floating point representation:

Sign 0 (a positive number)


Exponent (unadjusted): -39


Mantissa (not normalized):
1.1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


8. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


Exponent (unadjusted) + 2(11-1) - 1 =


-39 + 2(11-1) - 1 =


(-39 + 1 023)(10) =


984(10)


9. Convert the adjusted exponent from the decimal (base 10) to 11 bit binary.

Use the same technique of repeatedly dividing by 2:


  • division = quotient + remainder;
  • 984 ÷ 2 = 492 + 0;
  • 492 ÷ 2 = 246 + 0;
  • 246 ÷ 2 = 123 + 0;
  • 123 ÷ 2 = 61 + 1;
  • 61 ÷ 2 = 30 + 1;
  • 30 ÷ 2 = 15 + 0;
  • 15 ÷ 2 = 7 + 1;
  • 7 ÷ 2 = 3 + 1;
  • 3 ÷ 2 = 1 + 1;
  • 1 ÷ 2 = 0 + 1;

10. Construct the base 2 representation of the adjusted exponent.

Take all the remainders starting from the bottom of the list constructed above.


Exponent (adjusted) =


984(10) =


011 1101 1000(2)


11. Normalize the mantissa.

a) Remove the leading (the leftmost) bit, since it's allways 1, and the decimal point, if the case.


b) Adjust its length to 52 bits, only if necessary (not the case here).


Mantissa (normalized) =


1. 1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001 =


1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


12. The three elements that make up the number's 64 bit double precision IEEE 754 binary floating point representation:

Sign (1 bit) =
0 (a positive number)


Exponent (11 bits) =
011 1101 1000


Mantissa (52 bits) =
1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


Decimal number 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 987 8 converted to 64 bit double precision IEEE 754 binary floating point representation:

0 - 011 1101 1000 - 1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


How to convert numbers from the decimal system (base ten) to 64 bit double precision IEEE 754 binary floating point standard

Follow the steps below to convert a base 10 decimal number to 64 bit double precision IEEE 754 binary floating point:

  • 1. If the number to be converted is negative, start with its the positive version.
  • 2. First convert the integer part. Divide repeatedly by 2 the positive representation of the integer number that is to be converted to binary, until we get a quotient that is equal to zero, keeping track of each remainder.
  • 3. Construct the base 2 representation of the positive integer part of the number, by taking all the remainders from the previous operations, starting from the bottom of the list constructed above. Thus, the last remainder of the divisions becomes the first symbol (the leftmost) of the base two number, while the first remainder becomes the last symbol (the rightmost).
  • 4. Then convert the fractional part. Multiply the number repeatedly by 2, until we get a fractional part that is equal to zero, keeping track of each integer part of the results.
  • 5. Construct the base 2 representation of the fractional part of the number, by taking all the integer parts of the multiplying operations, starting from the top of the list constructed above (they should appear in the binary representation, from left to right, in the order they have been calculated).
  • 6. Normalize the binary representation of the number, shifting the decimal mark (the decimal point) "n" positions either to the left, or to the right, so that only one non zero digit remains to the left of the decimal mark.
  • 7. Adjust the exponent in 11 bit excess/bias notation and then convert it from decimal (base 10) to 11 bit binary, by using the same technique of repeatedly dividing by 2, as shown above:
    Exponent (adjusted) = Exponent (unadjusted) + 2(11-1) - 1
  • 8. Normalize mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal mark, if the case) and adjust its length to 52 bits, either by removing the excess bits from the right (losing precision...) or by adding extra bits set on '0' to the right.
  • 9. Sign (it takes 1 bit) is either 1 for a negative or 0 for a positive number.

Example: convert the negative number -31.640 215 from the decimal system (base ten) to 64 bit double precision IEEE 754 binary floating point:

  • 1. Start with the positive version of the number:

    |-31.640 215| = 31.640 215

  • 2. First convert the integer part, 31. Divide it repeatedly by 2, keeping track of each remainder, until we get a quotient that is equal to zero:
    • division = quotient + remainder;
    • 31 ÷ 2 = 15 + 1;
    • 15 ÷ 2 = 7 + 1;
    • 7 ÷ 2 = 3 + 1;
    • 3 ÷ 2 = 1 + 1;
    • 1 ÷ 2 = 0 + 1;
    • We have encountered a quotient that is ZERO => FULL STOP
  • 3. Construct the base 2 representation of the integer part of the number by taking all the remainders of the previous dividing operations, starting from the bottom of the list constructed above:

    31(10) = 1 1111(2)

  • 4. Then, convert the fractional part, 0.640 215. Multiply repeatedly by 2, keeping track of each integer part of the results, until we get a fractional part that is equal to zero:
    • #) multiplying = integer + fractional part;
    • 1) 0.640 215 × 2 = 1 + 0.280 43;
    • 2) 0.280 43 × 2 = 0 + 0.560 86;
    • 3) 0.560 86 × 2 = 1 + 0.121 72;
    • 4) 0.121 72 × 2 = 0 + 0.243 44;
    • 5) 0.243 44 × 2 = 0 + 0.486 88;
    • 6) 0.486 88 × 2 = 0 + 0.973 76;
    • 7) 0.973 76 × 2 = 1 + 0.947 52;
    • 8) 0.947 52 × 2 = 1 + 0.895 04;
    • 9) 0.895 04 × 2 = 1 + 0.790 08;
    • 10) 0.790 08 × 2 = 1 + 0.580 16;
    • 11) 0.580 16 × 2 = 1 + 0.160 32;
    • 12) 0.160 32 × 2 = 0 + 0.320 64;
    • 13) 0.320 64 × 2 = 0 + 0.641 28;
    • 14) 0.641 28 × 2 = 1 + 0.282 56;
    • 15) 0.282 56 × 2 = 0 + 0.565 12;
    • 16) 0.565 12 × 2 = 1 + 0.130 24;
    • 17) 0.130 24 × 2 = 0 + 0.260 48;
    • 18) 0.260 48 × 2 = 0 + 0.520 96;
    • 19) 0.520 96 × 2 = 1 + 0.041 92;
    • 20) 0.041 92 × 2 = 0 + 0.083 84;
    • 21) 0.083 84 × 2 = 0 + 0.167 68;
    • 22) 0.167 68 × 2 = 0 + 0.335 36;
    • 23) 0.335 36 × 2 = 0 + 0.670 72;
    • 24) 0.670 72 × 2 = 1 + 0.341 44;
    • 25) 0.341 44 × 2 = 0 + 0.682 88;
    • 26) 0.682 88 × 2 = 1 + 0.365 76;
    • 27) 0.365 76 × 2 = 0 + 0.731 52;
    • 28) 0.731 52 × 2 = 1 + 0.463 04;
    • 29) 0.463 04 × 2 = 0 + 0.926 08;
    • 30) 0.926 08 × 2 = 1 + 0.852 16;
    • 31) 0.852 16 × 2 = 1 + 0.704 32;
    • 32) 0.704 32 × 2 = 1 + 0.408 64;
    • 33) 0.408 64 × 2 = 0 + 0.817 28;
    • 34) 0.817 28 × 2 = 1 + 0.634 56;
    • 35) 0.634 56 × 2 = 1 + 0.269 12;
    • 36) 0.269 12 × 2 = 0 + 0.538 24;
    • 37) 0.538 24 × 2 = 1 + 0.076 48;
    • 38) 0.076 48 × 2 = 0 + 0.152 96;
    • 39) 0.152 96 × 2 = 0 + 0.305 92;
    • 40) 0.305 92 × 2 = 0 + 0.611 84;
    • 41) 0.611 84 × 2 = 1 + 0.223 68;
    • 42) 0.223 68 × 2 = 0 + 0.447 36;
    • 43) 0.447 36 × 2 = 0 + 0.894 72;
    • 44) 0.894 72 × 2 = 1 + 0.789 44;
    • 45) 0.789 44 × 2 = 1 + 0.578 88;
    • 46) 0.578 88 × 2 = 1 + 0.157 76;
    • 47) 0.157 76 × 2 = 0 + 0.315 52;
    • 48) 0.315 52 × 2 = 0 + 0.631 04;
    • 49) 0.631 04 × 2 = 1 + 0.262 08;
    • 50) 0.262 08 × 2 = 0 + 0.524 16;
    • 51) 0.524 16 × 2 = 1 + 0.048 32;
    • 52) 0.048 32 × 2 = 0 + 0.096 64;
    • 53) 0.096 64 × 2 = 0 + 0.193 28;
    • We didn't get any fractional part that was equal to zero. But we had enough iterations (over Mantissa limit = 52) and at least one integer part that was different from zero => FULL STOP (losing precision...).
  • 5. Construct the base 2 representation of the fractional part of the number, by taking all the integer parts of the previous multiplying operations, starting from the top of the constructed list above:

    0.640 215(10) = 0.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2)

  • 6. Summarizing - the positive number before normalization:

    31.640 215(10) = 1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2)

  • 7. Normalize the binary representation of the number, shifting the decimal mark 4 positions to the left so that only one non-zero digit stays to the left of the decimal mark:

    31.640 215(10) =
    1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) =
    1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) × 20 =
    1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) × 24

  • 8. Up to this moment, there are the following elements that would feed into the 64 bit double precision IEEE 754 binary floating point representation:

    Sign: 1 (a negative number)

    Exponent (unadjusted): 4

    Mantissa (not-normalized): 1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0

  • 9. Adjust the exponent in 11 bit excess/bias notation and then convert it from decimal (base 10) to 11 bit binary (base 2), by using the same technique of repeatedly dividing it by 2, as shown above:

    Exponent (adjusted) = Exponent (unadjusted) + 2(11-1) - 1 = (4 + 1023)(10) = 1027(10) =
    100 0000 0011(2)

  • 10. Normalize mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal sign) and adjust its length to 52 bits, by removing the excess bits, from the right (losing precision...):

    Mantissa (not-normalized): 1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0

    Mantissa (normalized): 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100

  • Conclusion:

    Sign (1 bit) = 1 (a negative number)

    Exponent (8 bits) = 100 0000 0011

    Mantissa (52 bits) = 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100

  • Number -31.640 215, converted from decimal system (base 10) to 64 bit double precision IEEE 754 binary floating point =
    1 - 100 0000 0011 - 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100