1.745 459 324 169 999 826 281 696 186 817 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 1.745 459 324 169 999 826 281 696 186 817(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
1.745 459 324 169 999 826 281 696 186 817(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: 0.745 459 324 169 999 826 281 696 186 817.

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) 0.745 459 324 169 999 826 281 696 186 817 × 2 = 1 + 0.490 918 648 339 999 652 563 392 373 634;
  • 2) 0.490 918 648 339 999 652 563 392 373 634 × 2 = 0 + 0.981 837 296 679 999 305 126 784 747 268;
  • 3) 0.981 837 296 679 999 305 126 784 747 268 × 2 = 1 + 0.963 674 593 359 998 610 253 569 494 536;
  • 4) 0.963 674 593 359 998 610 253 569 494 536 × 2 = 1 + 0.927 349 186 719 997 220 507 138 989 072;
  • 5) 0.927 349 186 719 997 220 507 138 989 072 × 2 = 1 + 0.854 698 373 439 994 441 014 277 978 144;
  • 6) 0.854 698 373 439 994 441 014 277 978 144 × 2 = 1 + 0.709 396 746 879 988 882 028 555 956 288;
  • 7) 0.709 396 746 879 988 882 028 555 956 288 × 2 = 1 + 0.418 793 493 759 977 764 057 111 912 576;
  • 8) 0.418 793 493 759 977 764 057 111 912 576 × 2 = 0 + 0.837 586 987 519 955 528 114 223 825 152;
  • 9) 0.837 586 987 519 955 528 114 223 825 152 × 2 = 1 + 0.675 173 975 039 911 056 228 447 650 304;
  • 10) 0.675 173 975 039 911 056 228 447 650 304 × 2 = 1 + 0.350 347 950 079 822 112 456 895 300 608;
  • 11) 0.350 347 950 079 822 112 456 895 300 608 × 2 = 0 + 0.700 695 900 159 644 224 913 790 601 216;
  • 12) 0.700 695 900 159 644 224 913 790 601 216 × 2 = 1 + 0.401 391 800 319 288 449 827 581 202 432;
  • 13) 0.401 391 800 319 288 449 827 581 202 432 × 2 = 0 + 0.802 783 600 638 576 899 655 162 404 864;
  • 14) 0.802 783 600 638 576 899 655 162 404 864 × 2 = 1 + 0.605 567 201 277 153 799 310 324 809 728;
  • 15) 0.605 567 201 277 153 799 310 324 809 728 × 2 = 1 + 0.211 134 402 554 307 598 620 649 619 456;
  • 16) 0.211 134 402 554 307 598 620 649 619 456 × 2 = 0 + 0.422 268 805 108 615 197 241 299 238 912;
  • 17) 0.422 268 805 108 615 197 241 299 238 912 × 2 = 0 + 0.844 537 610 217 230 394 482 598 477 824;
  • 18) 0.844 537 610 217 230 394 482 598 477 824 × 2 = 1 + 0.689 075 220 434 460 788 965 196 955 648;
  • 19) 0.689 075 220 434 460 788 965 196 955 648 × 2 = 1 + 0.378 150 440 868 921 577 930 393 911 296;
  • 20) 0.378 150 440 868 921 577 930 393 911 296 × 2 = 0 + 0.756 300 881 737 843 155 860 787 822 592;
  • 21) 0.756 300 881 737 843 155 860 787 822 592 × 2 = 1 + 0.512 601 763 475 686 311 721 575 645 184;
  • 22) 0.512 601 763 475 686 311 721 575 645 184 × 2 = 1 + 0.025 203 526 951 372 623 443 151 290 368;
  • 23) 0.025 203 526 951 372 623 443 151 290 368 × 2 = 0 + 0.050 407 053 902 745 246 886 302 580 736;
  • 24) 0.050 407 053 902 745 246 886 302 580 736 × 2 = 0 + 0.100 814 107 805 490 493 772 605 161 472;
  • 25) 0.100 814 107 805 490 493 772 605 161 472 × 2 = 0 + 0.201 628 215 610 980 987 545 210 322 944;
  • 26) 0.201 628 215 610 980 987 545 210 322 944 × 2 = 0 + 0.403 256 431 221 961 975 090 420 645 888;
  • 27) 0.403 256 431 221 961 975 090 420 645 888 × 2 = 0 + 0.806 512 862 443 923 950 180 841 291 776;
  • 28) 0.806 512 862 443 923 950 180 841 291 776 × 2 = 1 + 0.613 025 724 887 847 900 361 682 583 552;
  • 29) 0.613 025 724 887 847 900 361 682 583 552 × 2 = 1 + 0.226 051 449 775 695 800 723 365 167 104;
  • 30) 0.226 051 449 775 695 800 723 365 167 104 × 2 = 0 + 0.452 102 899 551 391 601 446 730 334 208;
  • 31) 0.452 102 899 551 391 601 446 730 334 208 × 2 = 0 + 0.904 205 799 102 783 202 893 460 668 416;
  • 32) 0.904 205 799 102 783 202 893 460 668 416 × 2 = 1 + 0.808 411 598 205 566 405 786 921 336 832;
  • 33) 0.808 411 598 205 566 405 786 921 336 832 × 2 = 1 + 0.616 823 196 411 132 811 573 842 673 664;
  • 34) 0.616 823 196 411 132 811 573 842 673 664 × 2 = 1 + 0.233 646 392 822 265 623 147 685 347 328;
  • 35) 0.233 646 392 822 265 623 147 685 347 328 × 2 = 0 + 0.467 292 785 644 531 246 295 370 694 656;
  • 36) 0.467 292 785 644 531 246 295 370 694 656 × 2 = 0 + 0.934 585 571 289 062 492 590 741 389 312;
  • 37) 0.934 585 571 289 062 492 590 741 389 312 × 2 = 1 + 0.869 171 142 578 124 985 181 482 778 624;
  • 38) 0.869 171 142 578 124 985 181 482 778 624 × 2 = 1 + 0.738 342 285 156 249 970 362 965 557 248;
  • 39) 0.738 342 285 156 249 970 362 965 557 248 × 2 = 1 + 0.476 684 570 312 499 940 725 931 114 496;
  • 40) 0.476 684 570 312 499 940 725 931 114 496 × 2 = 0 + 0.953 369 140 624 999 881 451 862 228 992;
  • 41) 0.953 369 140 624 999 881 451 862 228 992 × 2 = 1 + 0.906 738 281 249 999 762 903 724 457 984;
  • 42) 0.906 738 281 249 999 762 903 724 457 984 × 2 = 1 + 0.813 476 562 499 999 525 807 448 915 968;
  • 43) 0.813 476 562 499 999 525 807 448 915 968 × 2 = 1 + 0.626 953 124 999 999 051 614 897 831 936;
  • 44) 0.626 953 124 999 999 051 614 897 831 936 × 2 = 1 + 0.253 906 249 999 998 103 229 795 663 872;
  • 45) 0.253 906 249 999 998 103 229 795 663 872 × 2 = 0 + 0.507 812 499 999 996 206 459 591 327 744;
  • 46) 0.507 812 499 999 996 206 459 591 327 744 × 2 = 1 + 0.015 624 999 999 992 412 919 182 655 488;
  • 47) 0.015 624 999 999 992 412 919 182 655 488 × 2 = 0 + 0.031 249 999 999 984 825 838 365 310 976;
  • 48) 0.031 249 999 999 984 825 838 365 310 976 × 2 = 0 + 0.062 499 999 999 969 651 676 730 621 952;
  • 49) 0.062 499 999 999 969 651 676 730 621 952 × 2 = 0 + 0.124 999 999 999 939 303 353 461 243 904;
  • 50) 0.124 999 999 999 939 303 353 461 243 904 × 2 = 0 + 0.249 999 999 999 878 606 706 922 487 808;
  • 51) 0.249 999 999 999 878 606 706 922 487 808 × 2 = 0 + 0.499 999 999 999 757 213 413 844 975 616;
  • 52) 0.499 999 999 999 757 213 413 844 975 616 × 2 = 0 + 0.999 999 999 999 514 426 827 689 951 232;
  • 53) 0.999 999 999 999 514 426 827 689 951 232 × 2 = 1 + 0.999 999 999 999 028 853 655 379 902 464;

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:


0.745 459 324 169 999 826 281 696 186 817(10) =


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

5. Positive number before normalization:

1.745 459 324 169 999 826 281 696 186 817(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:


1.745 459 324 169 999 826 281 696 186 817(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 1.745 459 324 169 999 826 281 696 186 817 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