0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 86 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 86(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 86(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 86.

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 86 × 2 = 0 + 0.000 000 000 007 269 999 999 999 999 516 522 114 064 601 356 671 72;
  • 2) 0.000 000 000 007 269 999 999 999 999 516 522 114 064 601 356 671 72 × 2 = 0 + 0.000 000 000 014 539 999 999 999 999 033 044 228 129 202 713 343 44;
  • 3) 0.000 000 000 014 539 999 999 999 999 033 044 228 129 202 713 343 44 × 2 = 0 + 0.000 000 000 029 079 999 999 999 998 066 088 456 258 405 426 686 88;
  • 4) 0.000 000 000 029 079 999 999 999 998 066 088 456 258 405 426 686 88 × 2 = 0 + 0.000 000 000 058 159 999 999 999 996 132 176 912 516 810 853 373 76;
  • 5) 0.000 000 000 058 159 999 999 999 996 132 176 912 516 810 853 373 76 × 2 = 0 + 0.000 000 000 116 319 999 999 999 992 264 353 825 033 621 706 747 52;
  • 6) 0.000 000 000 116 319 999 999 999 992 264 353 825 033 621 706 747 52 × 2 = 0 + 0.000 000 000 232 639 999 999 999 984 528 707 650 067 243 413 495 04;
  • 7) 0.000 000 000 232 639 999 999 999 984 528 707 650 067 243 413 495 04 × 2 = 0 + 0.000 000 000 465 279 999 999 999 969 057 415 300 134 486 826 990 08;
  • 8) 0.000 000 000 465 279 999 999 999 969 057 415 300 134 486 826 990 08 × 2 = 0 + 0.000 000 000 930 559 999 999 999 938 114 830 600 268 973 653 980 16;
  • 9) 0.000 000 000 930 559 999 999 999 938 114 830 600 268 973 653 980 16 × 2 = 0 + 0.000 000 001 861 119 999 999 999 876 229 661 200 537 947 307 960 32;
  • 10) 0.000 000 001 861 119 999 999 999 876 229 661 200 537 947 307 960 32 × 2 = 0 + 0.000 000 003 722 239 999 999 999 752 459 322 401 075 894 615 920 64;
  • 11) 0.000 000 003 722 239 999 999 999 752 459 322 401 075 894 615 920 64 × 2 = 0 + 0.000 000 007 444 479 999 999 999 504 918 644 802 151 789 231 841 28;
  • 12) 0.000 000 007 444 479 999 999 999 504 918 644 802 151 789 231 841 28 × 2 = 0 + 0.000 000 014 888 959 999 999 999 009 837 289 604 303 578 463 682 56;
  • 13) 0.000 000 014 888 959 999 999 999 009 837 289 604 303 578 463 682 56 × 2 = 0 + 0.000 000 029 777 919 999 999 998 019 674 579 208 607 156 927 365 12;
  • 14) 0.000 000 029 777 919 999 999 998 019 674 579 208 607 156 927 365 12 × 2 = 0 + 0.000 000 059 555 839 999 999 996 039 349 158 417 214 313 854 730 24;
  • 15) 0.000 000 059 555 839 999 999 996 039 349 158 417 214 313 854 730 24 × 2 = 0 + 0.000 000 119 111 679 999 999 992 078 698 316 834 428 627 709 460 48;
  • 16) 0.000 000 119 111 679 999 999 992 078 698 316 834 428 627 709 460 48 × 2 = 0 + 0.000 000 238 223 359 999 999 984 157 396 633 668 857 255 418 920 96;
  • 17) 0.000 000 238 223 359 999 999 984 157 396 633 668 857 255 418 920 96 × 2 = 0 + 0.000 000 476 446 719 999 999 968 314 793 267 337 714 510 837 841 92;
  • 18) 0.000 000 476 446 719 999 999 968 314 793 267 337 714 510 837 841 92 × 2 = 0 + 0.000 000 952 893 439 999 999 936 629 586 534 675 429 021 675 683 84;
  • 19) 0.000 000 952 893 439 999 999 936 629 586 534 675 429 021 675 683 84 × 2 = 0 + 0.000 001 905 786 879 999 999 873 259 173 069 350 858 043 351 367 68;
  • 20) 0.000 001 905 786 879 999 999 873 259 173 069 350 858 043 351 367 68 × 2 = 0 + 0.000 003 811 573 759 999 999 746 518 346 138 701 716 086 702 735 36;
  • 21) 0.000 003 811 573 759 999 999 746 518 346 138 701 716 086 702 735 36 × 2 = 0 + 0.000 007 623 147 519 999 999 493 036 692 277 403 432 173 405 470 72;
  • 22) 0.000 007 623 147 519 999 999 493 036 692 277 403 432 173 405 470 72 × 2 = 0 + 0.000 015 246 295 039 999 998 986 073 384 554 806 864 346 810 941 44;
  • 23) 0.000 015 246 295 039 999 998 986 073 384 554 806 864 346 810 941 44 × 2 = 0 + 0.000 030 492 590 079 999 997 972 146 769 109 613 728 693 621 882 88;
  • 24) 0.000 030 492 590 079 999 997 972 146 769 109 613 728 693 621 882 88 × 2 = 0 + 0.000 060 985 180 159 999 995 944 293 538 219 227 457 387 243 765 76;
  • 25) 0.000 060 985 180 159 999 995 944 293 538 219 227 457 387 243 765 76 × 2 = 0 + 0.000 121 970 360 319 999 991 888 587 076 438 454 914 774 487 531 52;
  • 26) 0.000 121 970 360 319 999 991 888 587 076 438 454 914 774 487 531 52 × 2 = 0 + 0.000 243 940 720 639 999 983 777 174 152 876 909 829 548 975 063 04;
  • 27) 0.000 243 940 720 639 999 983 777 174 152 876 909 829 548 975 063 04 × 2 = 0 + 0.000 487 881 441 279 999 967 554 348 305 753 819 659 097 950 126 08;
  • 28) 0.000 487 881 441 279 999 967 554 348 305 753 819 659 097 950 126 08 × 2 = 0 + 0.000 975 762 882 559 999 935 108 696 611 507 639 318 195 900 252 16;
  • 29) 0.000 975 762 882 559 999 935 108 696 611 507 639 318 195 900 252 16 × 2 = 0 + 0.001 951 525 765 119 999 870 217 393 223 015 278 636 391 800 504 32;
  • 30) 0.001 951 525 765 119 999 870 217 393 223 015 278 636 391 800 504 32 × 2 = 0 + 0.003 903 051 530 239 999 740 434 786 446 030 557 272 783 601 008 64;
  • 31) 0.003 903 051 530 239 999 740 434 786 446 030 557 272 783 601 008 64 × 2 = 0 + 0.007 806 103 060 479 999 480 869 572 892 061 114 545 567 202 017 28;
  • 32) 0.007 806 103 060 479 999 480 869 572 892 061 114 545 567 202 017 28 × 2 = 0 + 0.015 612 206 120 959 998 961 739 145 784 122 229 091 134 404 034 56;
  • 33) 0.015 612 206 120 959 998 961 739 145 784 122 229 091 134 404 034 56 × 2 = 0 + 0.031 224 412 241 919 997 923 478 291 568 244 458 182 268 808 069 12;
  • 34) 0.031 224 412 241 919 997 923 478 291 568 244 458 182 268 808 069 12 × 2 = 0 + 0.062 448 824 483 839 995 846 956 583 136 488 916 364 537 616 138 24;
  • 35) 0.062 448 824 483 839 995 846 956 583 136 488 916 364 537 616 138 24 × 2 = 0 + 0.124 897 648 967 679 991 693 913 166 272 977 832 729 075 232 276 48;
  • 36) 0.124 897 648 967 679 991 693 913 166 272 977 832 729 075 232 276 48 × 2 = 0 + 0.249 795 297 935 359 983 387 826 332 545 955 665 458 150 464 552 96;
  • 37) 0.249 795 297 935 359 983 387 826 332 545 955 665 458 150 464 552 96 × 2 = 0 + 0.499 590 595 870 719 966 775 652 665 091 911 330 916 300 929 105 92;
  • 38) 0.499 590 595 870 719 966 775 652 665 091 911 330 916 300 929 105 92 × 2 = 0 + 0.999 181 191 741 439 933 551 305 330 183 822 661 832 601 858 211 84;
  • 39) 0.999 181 191 741 439 933 551 305 330 183 822 661 832 601 858 211 84 × 2 = 1 + 0.998 362 383 482 879 867 102 610 660 367 645 323 665 203 716 423 68;
  • 40) 0.998 362 383 482 879 867 102 610 660 367 645 323 665 203 716 423 68 × 2 = 1 + 0.996 724 766 965 759 734 205 221 320 735 290 647 330 407 432 847 36;
  • 41) 0.996 724 766 965 759 734 205 221 320 735 290 647 330 407 432 847 36 × 2 = 1 + 0.993 449 533 931 519 468 410 442 641 470 581 294 660 814 865 694 72;
  • 42) 0.993 449 533 931 519 468 410 442 641 470 581 294 660 814 865 694 72 × 2 = 1 + 0.986 899 067 863 038 936 820 885 282 941 162 589 321 629 731 389 44;
  • 43) 0.986 899 067 863 038 936 820 885 282 941 162 589 321 629 731 389 44 × 2 = 1 + 0.973 798 135 726 077 873 641 770 565 882 325 178 643 259 462 778 88;
  • 44) 0.973 798 135 726 077 873 641 770 565 882 325 178 643 259 462 778 88 × 2 = 1 + 0.947 596 271 452 155 747 283 541 131 764 650 357 286 518 925 557 76;
  • 45) 0.947 596 271 452 155 747 283 541 131 764 650 357 286 518 925 557 76 × 2 = 1 + 0.895 192 542 904 311 494 567 082 263 529 300 714 573 037 851 115 52;
  • 46) 0.895 192 542 904 311 494 567 082 263 529 300 714 573 037 851 115 52 × 2 = 1 + 0.790 385 085 808 622 989 134 164 527 058 601 429 146 075 702 231 04;
  • 47) 0.790 385 085 808 622 989 134 164 527 058 601 429 146 075 702 231 04 × 2 = 1 + 0.580 770 171 617 245 978 268 329 054 117 202 858 292 151 404 462 08;
  • 48) 0.580 770 171 617 245 978 268 329 054 117 202 858 292 151 404 462 08 × 2 = 1 + 0.161 540 343 234 491 956 536 658 108 234 405 716 584 302 808 924 16;
  • 49) 0.161 540 343 234 491 956 536 658 108 234 405 716 584 302 808 924 16 × 2 = 0 + 0.323 080 686 468 983 913 073 316 216 468 811 433 168 605 617 848 32;
  • 50) 0.323 080 686 468 983 913 073 316 216 468 811 433 168 605 617 848 32 × 2 = 0 + 0.646 161 372 937 967 826 146 632 432 937 622 866 337 211 235 696 64;
  • 51) 0.646 161 372 937 967 826 146 632 432 937 622 866 337 211 235 696 64 × 2 = 1 + 0.292 322 745 875 935 652 293 264 865 875 245 732 674 422 471 393 28;
  • 52) 0.292 322 745 875 935 652 293 264 865 875 245 732 674 422 471 393 28 × 2 = 0 + 0.584 645 491 751 871 304 586 529 731 750 491 465 348 844 942 786 56;
  • 53) 0.584 645 491 751 871 304 586 529 731 750 491 465 348 844 942 786 56 × 2 = 1 + 0.169 290 983 503 742 609 173 059 463 500 982 930 697 689 885 573 12;
  • 54) 0.169 290 983 503 742 609 173 059 463 500 982 930 697 689 885 573 12 × 2 = 0 + 0.338 581 967 007 485 218 346 118 927 001 965 861 395 379 771 146 24;
  • 55) 0.338 581 967 007 485 218 346 118 927 001 965 861 395 379 771 146 24 × 2 = 0 + 0.677 163 934 014 970 436 692 237 854 003 931 722 790 759 542 292 48;
  • 56) 0.677 163 934 014 970 436 692 237 854 003 931 722 790 759 542 292 48 × 2 = 1 + 0.354 327 868 029 940 873 384 475 708 007 863 445 581 519 084 584 96;
  • 57) 0.354 327 868 029 940 873 384 475 708 007 863 445 581 519 084 584 96 × 2 = 0 + 0.708 655 736 059 881 746 768 951 416 015 726 891 163 038 169 169 92;
  • 58) 0.708 655 736 059 881 746 768 951 416 015 726 891 163 038 169 169 92 × 2 = 1 + 0.417 311 472 119 763 493 537 902 832 031 453 782 326 076 338 339 84;
  • 59) 0.417 311 472 119 763 493 537 902 832 031 453 782 326 076 338 339 84 × 2 = 0 + 0.834 622 944 239 526 987 075 805 664 062 907 564 652 152 676 679 68;
  • 60) 0.834 622 944 239 526 987 075 805 664 062 907 564 652 152 676 679 68 × 2 = 1 + 0.669 245 888 479 053 974 151 611 328 125 815 129 304 305 353 359 36;
  • 61) 0.669 245 888 479 053 974 151 611 328 125 815 129 304 305 353 359 36 × 2 = 1 + 0.338 491 776 958 107 948 303 222 656 251 630 258 608 610 706 718 72;
  • 62) 0.338 491 776 958 107 948 303 222 656 251 630 258 608 610 706 718 72 × 2 = 0 + 0.676 983 553 916 215 896 606 445 312 503 260 517 217 221 413 437 44;
  • 63) 0.676 983 553 916 215 896 606 445 312 503 260 517 217 221 413 437 44 × 2 = 1 + 0.353 967 107 832 431 793 212 890 625 006 521 034 434 442 826 874 88;
  • 64) 0.353 967 107 832 431 793 212 890 625 006 521 034 434 442 826 874 88 × 2 = 0 + 0.707 934 215 664 863 586 425 781 250 013 042 068 868 885 653 749 76;
  • 65) 0.707 934 215 664 863 586 425 781 250 013 042 068 868 885 653 749 76 × 2 = 1 + 0.415 868 431 329 727 172 851 562 500 026 084 137 737 771 307 499 52;
  • 66) 0.415 868 431 329 727 172 851 562 500 026 084 137 737 771 307 499 52 × 2 = 0 + 0.831 736 862 659 454 345 703 125 000 052 168 275 475 542 614 999 04;
  • 67) 0.831 736 862 659 454 345 703 125 000 052 168 275 475 542 614 999 04 × 2 = 1 + 0.663 473 725 318 908 691 406 250 000 104 336 550 951 085 229 998 08;
  • 68) 0.663 473 725 318 908 691 406 250 000 104 336 550 951 085 229 998 08 × 2 = 1 + 0.326 947 450 637 817 382 812 500 000 208 673 101 902 170 459 996 16;
  • 69) 0.326 947 450 637 817 382 812 500 000 208 673 101 902 170 459 996 16 × 2 = 0 + 0.653 894 901 275 634 765 625 000 000 417 346 203 804 340 919 992 32;
  • 70) 0.653 894 901 275 634 765 625 000 000 417 346 203 804 340 919 992 32 × 2 = 1 + 0.307 789 802 551 269 531 250 000 000 834 692 407 608 681 839 984 64;
  • 71) 0.307 789 802 551 269 531 250 000 000 834 692 407 608 681 839 984 64 × 2 = 0 + 0.615 579 605 102 539 062 500 000 001 669 384 815 217 363 679 969 28;
  • 72) 0.615 579 605 102 539 062 500 000 001 669 384 815 217 363 679 969 28 × 2 = 1 + 0.231 159 210 205 078 125 000 000 003 338 769 630 434 727 359 938 56;
  • 73) 0.231 159 210 205 078 125 000 000 003 338 769 630 434 727 359 938 56 × 2 = 0 + 0.462 318 420 410 156 250 000 000 006 677 539 260 869 454 719 877 12;
  • 74) 0.462 318 420 410 156 250 000 000 006 677 539 260 869 454 719 877 12 × 2 = 0 + 0.924 636 840 820 312 500 000 000 013 355 078 521 738 909 439 754 24;
  • 75) 0.924 636 840 820 312 500 000 000 013 355 078 521 738 909 439 754 24 × 2 = 1 + 0.849 273 681 640 625 000 000 000 026 710 157 043 477 818 879 508 48;
  • 76) 0.849 273 681 640 625 000 000 000 026 710 157 043 477 818 879 508 48 × 2 = 1 + 0.698 547 363 281 250 000 000 000 053 420 314 086 955 637 759 016 96;
  • 77) 0.698 547 363 281 250 000 000 000 053 420 314 086 955 637 759 016 96 × 2 = 1 + 0.397 094 726 562 500 000 000 000 106 840 628 173 911 275 518 033 92;
  • 78) 0.397 094 726 562 500 000 000 000 106 840 628 173 911 275 518 033 92 × 2 = 0 + 0.794 189 453 125 000 000 000 000 213 681 256 347 822 551 036 067 84;
  • 79) 0.794 189 453 125 000 000 000 000 213 681 256 347 822 551 036 067 84 × 2 = 1 + 0.588 378 906 250 000 000 000 000 427 362 512 695 645 102 072 135 68;
  • 80) 0.588 378 906 250 000 000 000 000 427 362 512 695 645 102 072 135 68 × 2 = 1 + 0.176 757 812 500 000 000 000 000 854 725 025 391 290 204 144 271 36;
  • 81) 0.176 757 812 500 000 000 000 000 854 725 025 391 290 204 144 271 36 × 2 = 0 + 0.353 515 625 000 000 000 000 001 709 450 050 782 580 408 288 542 72;
  • 82) 0.353 515 625 000 000 000 000 001 709 450 050 782 580 408 288 542 72 × 2 = 0 + 0.707 031 250 000 000 000 000 003 418 900 101 565 160 816 577 085 44;
  • 83) 0.707 031 250 000 000 000 000 003 418 900 101 565 160 816 577 085 44 × 2 = 1 + 0.414 062 500 000 000 000 000 006 837 800 203 130 321 633 154 170 88;
  • 84) 0.414 062 500 000 000 000 000 006 837 800 203 130 321 633 154 170 88 × 2 = 0 + 0.828 125 000 000 000 000 000 013 675 600 406 260 643 266 308 341 76;
  • 85) 0.828 125 000 000 000 000 000 013 675 600 406 260 643 266 308 341 76 × 2 = 1 + 0.656 250 000 000 000 000 000 027 351 200 812 521 286 532 616 683 52;
  • 86) 0.656 250 000 000 000 000 000 027 351 200 812 521 286 532 616 683 52 × 2 = 1 + 0.312 500 000 000 000 000 000 054 702 401 625 042 573 065 233 367 04;
  • 87) 0.312 500 000 000 000 000 000 054 702 401 625 042 573 065 233 367 04 × 2 = 0 + 0.625 000 000 000 000 000 000 109 404 803 250 085 146 130 466 734 08;
  • 88) 0.625 000 000 000 000 000 000 109 404 803 250 085 146 130 466 734 08 × 2 = 1 + 0.250 000 000 000 000 000 000 218 809 606 500 170 292 260 933 468 16;
  • 89) 0.250 000 000 000 000 000 000 218 809 606 500 170 292 260 933 468 16 × 2 = 0 + 0.500 000 000 000 000 000 000 437 619 213 000 340 584 521 866 936 32;
  • 90) 0.500 000 000 000 000 000 000 437 619 213 000 340 584 521 866 936 32 × 2 = 1 + 0.000 000 000 000 000 000 000 875 238 426 000 681 169 043 733 872 64;
  • 91) 0.000 000 000 000 000 000 000 875 238 426 000 681 169 043 733 872 64 × 2 = 0 + 0.000 000 000 000 000 000 001 750 476 852 001 362 338 087 467 745 28;

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 86(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 010(2)

5. Positive number before normalization:

0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 86(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 010(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 86(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 010(2) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 010(2) × 20 =


1.1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1010(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 1010


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 1010 =


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


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 1010


Decimal number 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 86 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 1010


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