1.745 459 324 169 999 826 281 696 186 924 816 31 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 1.745 459 324 169 999 826 281 696 186 924 816 31(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
1.745 459 324 169 999 826 281 696 186 924 816 31(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: 1.
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;
  • 1 ÷ 2 = 0 + 1;

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.

1(10) =


1(2)


3. Convert to binary (base 2) the fractional part: 0.745 459 324 169 999 826 281 696 186 924 816 31.

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) 0.745 459 324 169 999 826 281 696 186 924 816 31 × 2 = 1 + 0.490 918 648 339 999 652 563 392 373 849 632 62;
  • 2) 0.490 918 648 339 999 652 563 392 373 849 632 62 × 2 = 0 + 0.981 837 296 679 999 305 126 784 747 699 265 24;
  • 3) 0.981 837 296 679 999 305 126 784 747 699 265 24 × 2 = 1 + 0.963 674 593 359 998 610 253 569 495 398 530 48;
  • 4) 0.963 674 593 359 998 610 253 569 495 398 530 48 × 2 = 1 + 0.927 349 186 719 997 220 507 138 990 797 060 96;
  • 5) 0.927 349 186 719 997 220 507 138 990 797 060 96 × 2 = 1 + 0.854 698 373 439 994 441 014 277 981 594 121 92;
  • 6) 0.854 698 373 439 994 441 014 277 981 594 121 92 × 2 = 1 + 0.709 396 746 879 988 882 028 555 963 188 243 84;
  • 7) 0.709 396 746 879 988 882 028 555 963 188 243 84 × 2 = 1 + 0.418 793 493 759 977 764 057 111 926 376 487 68;
  • 8) 0.418 793 493 759 977 764 057 111 926 376 487 68 × 2 = 0 + 0.837 586 987 519 955 528 114 223 852 752 975 36;
  • 9) 0.837 586 987 519 955 528 114 223 852 752 975 36 × 2 = 1 + 0.675 173 975 039 911 056 228 447 705 505 950 72;
  • 10) 0.675 173 975 039 911 056 228 447 705 505 950 72 × 2 = 1 + 0.350 347 950 079 822 112 456 895 411 011 901 44;
  • 11) 0.350 347 950 079 822 112 456 895 411 011 901 44 × 2 = 0 + 0.700 695 900 159 644 224 913 790 822 023 802 88;
  • 12) 0.700 695 900 159 644 224 913 790 822 023 802 88 × 2 = 1 + 0.401 391 800 319 288 449 827 581 644 047 605 76;
  • 13) 0.401 391 800 319 288 449 827 581 644 047 605 76 × 2 = 0 + 0.802 783 600 638 576 899 655 163 288 095 211 52;
  • 14) 0.802 783 600 638 576 899 655 163 288 095 211 52 × 2 = 1 + 0.605 567 201 277 153 799 310 326 576 190 423 04;
  • 15) 0.605 567 201 277 153 799 310 326 576 190 423 04 × 2 = 1 + 0.211 134 402 554 307 598 620 653 152 380 846 08;
  • 16) 0.211 134 402 554 307 598 620 653 152 380 846 08 × 2 = 0 + 0.422 268 805 108 615 197 241 306 304 761 692 16;
  • 17) 0.422 268 805 108 615 197 241 306 304 761 692 16 × 2 = 0 + 0.844 537 610 217 230 394 482 612 609 523 384 32;
  • 18) 0.844 537 610 217 230 394 482 612 609 523 384 32 × 2 = 1 + 0.689 075 220 434 460 788 965 225 219 046 768 64;
  • 19) 0.689 075 220 434 460 788 965 225 219 046 768 64 × 2 = 1 + 0.378 150 440 868 921 577 930 450 438 093 537 28;
  • 20) 0.378 150 440 868 921 577 930 450 438 093 537 28 × 2 = 0 + 0.756 300 881 737 843 155 860 900 876 187 074 56;
  • 21) 0.756 300 881 737 843 155 860 900 876 187 074 56 × 2 = 1 + 0.512 601 763 475 686 311 721 801 752 374 149 12;
  • 22) 0.512 601 763 475 686 311 721 801 752 374 149 12 × 2 = 1 + 0.025 203 526 951 372 623 443 603 504 748 298 24;
  • 23) 0.025 203 526 951 372 623 443 603 504 748 298 24 × 2 = 0 + 0.050 407 053 902 745 246 887 207 009 496 596 48;
  • 24) 0.050 407 053 902 745 246 887 207 009 496 596 48 × 2 = 0 + 0.100 814 107 805 490 493 774 414 018 993 192 96;
  • 25) 0.100 814 107 805 490 493 774 414 018 993 192 96 × 2 = 0 + 0.201 628 215 610 980 987 548 828 037 986 385 92;
  • 26) 0.201 628 215 610 980 987 548 828 037 986 385 92 × 2 = 0 + 0.403 256 431 221 961 975 097 656 075 972 771 84;
  • 27) 0.403 256 431 221 961 975 097 656 075 972 771 84 × 2 = 0 + 0.806 512 862 443 923 950 195 312 151 945 543 68;
  • 28) 0.806 512 862 443 923 950 195 312 151 945 543 68 × 2 = 1 + 0.613 025 724 887 847 900 390 624 303 891 087 36;
  • 29) 0.613 025 724 887 847 900 390 624 303 891 087 36 × 2 = 1 + 0.226 051 449 775 695 800 781 248 607 782 174 72;
  • 30) 0.226 051 449 775 695 800 781 248 607 782 174 72 × 2 = 0 + 0.452 102 899 551 391 601 562 497 215 564 349 44;
  • 31) 0.452 102 899 551 391 601 562 497 215 564 349 44 × 2 = 0 + 0.904 205 799 102 783 203 124 994 431 128 698 88;
  • 32) 0.904 205 799 102 783 203 124 994 431 128 698 88 × 2 = 1 + 0.808 411 598 205 566 406 249 988 862 257 397 76;
  • 33) 0.808 411 598 205 566 406 249 988 862 257 397 76 × 2 = 1 + 0.616 823 196 411 132 812 499 977 724 514 795 52;
  • 34) 0.616 823 196 411 132 812 499 977 724 514 795 52 × 2 = 1 + 0.233 646 392 822 265 624 999 955 449 029 591 04;
  • 35) 0.233 646 392 822 265 624 999 955 449 029 591 04 × 2 = 0 + 0.467 292 785 644 531 249 999 910 898 059 182 08;
  • 36) 0.467 292 785 644 531 249 999 910 898 059 182 08 × 2 = 0 + 0.934 585 571 289 062 499 999 821 796 118 364 16;
  • 37) 0.934 585 571 289 062 499 999 821 796 118 364 16 × 2 = 1 + 0.869 171 142 578 124 999 999 643 592 236 728 32;
  • 38) 0.869 171 142 578 124 999 999 643 592 236 728 32 × 2 = 1 + 0.738 342 285 156 249 999 999 287 184 473 456 64;
  • 39) 0.738 342 285 156 249 999 999 287 184 473 456 64 × 2 = 1 + 0.476 684 570 312 499 999 998 574 368 946 913 28;
  • 40) 0.476 684 570 312 499 999 998 574 368 946 913 28 × 2 = 0 + 0.953 369 140 624 999 999 997 148 737 893 826 56;
  • 41) 0.953 369 140 624 999 999 997 148 737 893 826 56 × 2 = 1 + 0.906 738 281 249 999 999 994 297 475 787 653 12;
  • 42) 0.906 738 281 249 999 999 994 297 475 787 653 12 × 2 = 1 + 0.813 476 562 499 999 999 988 594 951 575 306 24;
  • 43) 0.813 476 562 499 999 999 988 594 951 575 306 24 × 2 = 1 + 0.626 953 124 999 999 999 977 189 903 150 612 48;
  • 44) 0.626 953 124 999 999 999 977 189 903 150 612 48 × 2 = 1 + 0.253 906 249 999 999 999 954 379 806 301 224 96;
  • 45) 0.253 906 249 999 999 999 954 379 806 301 224 96 × 2 = 0 + 0.507 812 499 999 999 999 908 759 612 602 449 92;
  • 46) 0.507 812 499 999 999 999 908 759 612 602 449 92 × 2 = 1 + 0.015 624 999 999 999 999 817 519 225 204 899 84;
  • 47) 0.015 624 999 999 999 999 817 519 225 204 899 84 × 2 = 0 + 0.031 249 999 999 999 999 635 038 450 409 799 68;
  • 48) 0.031 249 999 999 999 999 635 038 450 409 799 68 × 2 = 0 + 0.062 499 999 999 999 999 270 076 900 819 599 36;
  • 49) 0.062 499 999 999 999 999 270 076 900 819 599 36 × 2 = 0 + 0.124 999 999 999 999 998 540 153 801 639 198 72;
  • 50) 0.124 999 999 999 999 998 540 153 801 639 198 72 × 2 = 0 + 0.249 999 999 999 999 997 080 307 603 278 397 44;
  • 51) 0.249 999 999 999 999 997 080 307 603 278 397 44 × 2 = 0 + 0.499 999 999 999 999 994 160 615 206 556 794 88;
  • 52) 0.499 999 999 999 999 994 160 615 206 556 794 88 × 2 = 0 + 0.999 999 999 999 999 988 321 230 413 113 589 76;
  • 53) 0.999 999 999 999 999 988 321 230 413 113 589 76 × 2 = 1 + 0.999 999 999 999 999 976 642 460 826 227 179 52;

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:


0.745 459 324 169 999 826 281 696 186 924 816 31(10) =


0.1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000 1(2)

5. Positive number before normalization:

1.745 459 324 169 999 826 281 696 186 924 816 31(10) =


1.1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000 1(2)

6. Normalize the binary representation of the number.

Shift the decimal mark 0 positions to the left, so that only one non zero digit remains to the left of it:


1.745 459 324 169 999 826 281 696 186 924 816 31(10) =


1.1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000 1(2) =


1.1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000 1(2) × 20


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): 0


Mantissa (not normalized):
1.1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000 1


8. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


0 + 2(11-1) - 1 =


(0 + 1 023)(10) =


1 023(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;
  • 1 023 ÷ 2 = 511 + 1;
  • 511 ÷ 2 = 255 + 1;
  • 255 ÷ 2 = 127 + 1;
  • 127 ÷ 2 = 63 + 1;
  • 63 ÷ 2 = 31 + 1;
  • 31 ÷ 2 = 15 + 1;
  • 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) =


1023(10) =


011 1111 1111(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, by removing the excess bits, from the right (if any of the excess bits is set on 1, we are losing precision...).


Mantissa (normalized) =


1. 1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000 1 =


1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000


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 1111 1111


Mantissa (52 bits) =
1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000


Decimal number 1.745 459 324 169 999 826 281 696 186 924 816 31 converted to 64 bit double precision IEEE 754 binary floating point representation:

0 - 011 1111 1111 - 1011 1110 1101 0110 0110 1100 0001 1001 1100 1110 1111 0100 0000


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