1.745 459 324 169 999 826 281 696 186 832 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 1.745 459 324 169 999 826 281 696 186 832(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
1.745 459 324 169 999 826 281 696 186 832(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: 0.745 459 324 169 999 826 281 696 186 832.

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) 0.745 459 324 169 999 826 281 696 186 832 × 2 = 1 + 0.490 918 648 339 999 652 563 392 373 664;
  • 2) 0.490 918 648 339 999 652 563 392 373 664 × 2 = 0 + 0.981 837 296 679 999 305 126 784 747 328;
  • 3) 0.981 837 296 679 999 305 126 784 747 328 × 2 = 1 + 0.963 674 593 359 998 610 253 569 494 656;
  • 4) 0.963 674 593 359 998 610 253 569 494 656 × 2 = 1 + 0.927 349 186 719 997 220 507 138 989 312;
  • 5) 0.927 349 186 719 997 220 507 138 989 312 × 2 = 1 + 0.854 698 373 439 994 441 014 277 978 624;
  • 6) 0.854 698 373 439 994 441 014 277 978 624 × 2 = 1 + 0.709 396 746 879 988 882 028 555 957 248;
  • 7) 0.709 396 746 879 988 882 028 555 957 248 × 2 = 1 + 0.418 793 493 759 977 764 057 111 914 496;
  • 8) 0.418 793 493 759 977 764 057 111 914 496 × 2 = 0 + 0.837 586 987 519 955 528 114 223 828 992;
  • 9) 0.837 586 987 519 955 528 114 223 828 992 × 2 = 1 + 0.675 173 975 039 911 056 228 447 657 984;
  • 10) 0.675 173 975 039 911 056 228 447 657 984 × 2 = 1 + 0.350 347 950 079 822 112 456 895 315 968;
  • 11) 0.350 347 950 079 822 112 456 895 315 968 × 2 = 0 + 0.700 695 900 159 644 224 913 790 631 936;
  • 12) 0.700 695 900 159 644 224 913 790 631 936 × 2 = 1 + 0.401 391 800 319 288 449 827 581 263 872;
  • 13) 0.401 391 800 319 288 449 827 581 263 872 × 2 = 0 + 0.802 783 600 638 576 899 655 162 527 744;
  • 14) 0.802 783 600 638 576 899 655 162 527 744 × 2 = 1 + 0.605 567 201 277 153 799 310 325 055 488;
  • 15) 0.605 567 201 277 153 799 310 325 055 488 × 2 = 1 + 0.211 134 402 554 307 598 620 650 110 976;
  • 16) 0.211 134 402 554 307 598 620 650 110 976 × 2 = 0 + 0.422 268 805 108 615 197 241 300 221 952;
  • 17) 0.422 268 805 108 615 197 241 300 221 952 × 2 = 0 + 0.844 537 610 217 230 394 482 600 443 904;
  • 18) 0.844 537 610 217 230 394 482 600 443 904 × 2 = 1 + 0.689 075 220 434 460 788 965 200 887 808;
  • 19) 0.689 075 220 434 460 788 965 200 887 808 × 2 = 1 + 0.378 150 440 868 921 577 930 401 775 616;
  • 20) 0.378 150 440 868 921 577 930 401 775 616 × 2 = 0 + 0.756 300 881 737 843 155 860 803 551 232;
  • 21) 0.756 300 881 737 843 155 860 803 551 232 × 2 = 1 + 0.512 601 763 475 686 311 721 607 102 464;
  • 22) 0.512 601 763 475 686 311 721 607 102 464 × 2 = 1 + 0.025 203 526 951 372 623 443 214 204 928;
  • 23) 0.025 203 526 951 372 623 443 214 204 928 × 2 = 0 + 0.050 407 053 902 745 246 886 428 409 856;
  • 24) 0.050 407 053 902 745 246 886 428 409 856 × 2 = 0 + 0.100 814 107 805 490 493 772 856 819 712;
  • 25) 0.100 814 107 805 490 493 772 856 819 712 × 2 = 0 + 0.201 628 215 610 980 987 545 713 639 424;
  • 26) 0.201 628 215 610 980 987 545 713 639 424 × 2 = 0 + 0.403 256 431 221 961 975 091 427 278 848;
  • 27) 0.403 256 431 221 961 975 091 427 278 848 × 2 = 0 + 0.806 512 862 443 923 950 182 854 557 696;
  • 28) 0.806 512 862 443 923 950 182 854 557 696 × 2 = 1 + 0.613 025 724 887 847 900 365 709 115 392;
  • 29) 0.613 025 724 887 847 900 365 709 115 392 × 2 = 1 + 0.226 051 449 775 695 800 731 418 230 784;
  • 30) 0.226 051 449 775 695 800 731 418 230 784 × 2 = 0 + 0.452 102 899 551 391 601 462 836 461 568;
  • 31) 0.452 102 899 551 391 601 462 836 461 568 × 2 = 0 + 0.904 205 799 102 783 202 925 672 923 136;
  • 32) 0.904 205 799 102 783 202 925 672 923 136 × 2 = 1 + 0.808 411 598 205 566 405 851 345 846 272;
  • 33) 0.808 411 598 205 566 405 851 345 846 272 × 2 = 1 + 0.616 823 196 411 132 811 702 691 692 544;
  • 34) 0.616 823 196 411 132 811 702 691 692 544 × 2 = 1 + 0.233 646 392 822 265 623 405 383 385 088;
  • 35) 0.233 646 392 822 265 623 405 383 385 088 × 2 = 0 + 0.467 292 785 644 531 246 810 766 770 176;
  • 36) 0.467 292 785 644 531 246 810 766 770 176 × 2 = 0 + 0.934 585 571 289 062 493 621 533 540 352;
  • 37) 0.934 585 571 289 062 493 621 533 540 352 × 2 = 1 + 0.869 171 142 578 124 987 243 067 080 704;
  • 38) 0.869 171 142 578 124 987 243 067 080 704 × 2 = 1 + 0.738 342 285 156 249 974 486 134 161 408;
  • 39) 0.738 342 285 156 249 974 486 134 161 408 × 2 = 1 + 0.476 684 570 312 499 948 972 268 322 816;
  • 40) 0.476 684 570 312 499 948 972 268 322 816 × 2 = 0 + 0.953 369 140 624 999 897 944 536 645 632;
  • 41) 0.953 369 140 624 999 897 944 536 645 632 × 2 = 1 + 0.906 738 281 249 999 795 889 073 291 264;
  • 42) 0.906 738 281 249 999 795 889 073 291 264 × 2 = 1 + 0.813 476 562 499 999 591 778 146 582 528;
  • 43) 0.813 476 562 499 999 591 778 146 582 528 × 2 = 1 + 0.626 953 124 999 999 183 556 293 165 056;
  • 44) 0.626 953 124 999 999 183 556 293 165 056 × 2 = 1 + 0.253 906 249 999 998 367 112 586 330 112;
  • 45) 0.253 906 249 999 998 367 112 586 330 112 × 2 = 0 + 0.507 812 499 999 996 734 225 172 660 224;
  • 46) 0.507 812 499 999 996 734 225 172 660 224 × 2 = 1 + 0.015 624 999 999 993 468 450 345 320 448;
  • 47) 0.015 624 999 999 993 468 450 345 320 448 × 2 = 0 + 0.031 249 999 999 986 936 900 690 640 896;
  • 48) 0.031 249 999 999 986 936 900 690 640 896 × 2 = 0 + 0.062 499 999 999 973 873 801 381 281 792;
  • 49) 0.062 499 999 999 973 873 801 381 281 792 × 2 = 0 + 0.124 999 999 999 947 747 602 762 563 584;
  • 50) 0.124 999 999 999 947 747 602 762 563 584 × 2 = 0 + 0.249 999 999 999 895 495 205 525 127 168;
  • 51) 0.249 999 999 999 895 495 205 525 127 168 × 2 = 0 + 0.499 999 999 999 790 990 411 050 254 336;
  • 52) 0.499 999 999 999 790 990 411 050 254 336 × 2 = 0 + 0.999 999 999 999 581 980 822 100 508 672;
  • 53) 0.999 999 999 999 581 980 822 100 508 672 × 2 = 1 + 0.999 999 999 999 163 961 644 201 017 344;

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:


0.745 459 324 169 999 826 281 696 186 832(10) =


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

5. Positive number before normalization:

1.745 459 324 169 999 826 281 696 186 832(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:


1.745 459 324 169 999 826 281 696 186 832(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 1.745 459 324 169 999 826 281 696 186 832 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