1.745 459 324 169 999 826 281 696 179 7 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 1.745 459 324 169 999 826 281 696 179 7(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
1.745 459 324 169 999 826 281 696 179 7(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: 0.745 459 324 169 999 826 281 696 179 7.

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) 0.745 459 324 169 999 826 281 696 179 7 × 2 = 1 + 0.490 918 648 339 999 652 563 392 359 4;
  • 2) 0.490 918 648 339 999 652 563 392 359 4 × 2 = 0 + 0.981 837 296 679 999 305 126 784 718 8;
  • 3) 0.981 837 296 679 999 305 126 784 718 8 × 2 = 1 + 0.963 674 593 359 998 610 253 569 437 6;
  • 4) 0.963 674 593 359 998 610 253 569 437 6 × 2 = 1 + 0.927 349 186 719 997 220 507 138 875 2;
  • 5) 0.927 349 186 719 997 220 507 138 875 2 × 2 = 1 + 0.854 698 373 439 994 441 014 277 750 4;
  • 6) 0.854 698 373 439 994 441 014 277 750 4 × 2 = 1 + 0.709 396 746 879 988 882 028 555 500 8;
  • 7) 0.709 396 746 879 988 882 028 555 500 8 × 2 = 1 + 0.418 793 493 759 977 764 057 111 001 6;
  • 8) 0.418 793 493 759 977 764 057 111 001 6 × 2 = 0 + 0.837 586 987 519 955 528 114 222 003 2;
  • 9) 0.837 586 987 519 955 528 114 222 003 2 × 2 = 1 + 0.675 173 975 039 911 056 228 444 006 4;
  • 10) 0.675 173 975 039 911 056 228 444 006 4 × 2 = 1 + 0.350 347 950 079 822 112 456 888 012 8;
  • 11) 0.350 347 950 079 822 112 456 888 012 8 × 2 = 0 + 0.700 695 900 159 644 224 913 776 025 6;
  • 12) 0.700 695 900 159 644 224 913 776 025 6 × 2 = 1 + 0.401 391 800 319 288 449 827 552 051 2;
  • 13) 0.401 391 800 319 288 449 827 552 051 2 × 2 = 0 + 0.802 783 600 638 576 899 655 104 102 4;
  • 14) 0.802 783 600 638 576 899 655 104 102 4 × 2 = 1 + 0.605 567 201 277 153 799 310 208 204 8;
  • 15) 0.605 567 201 277 153 799 310 208 204 8 × 2 = 1 + 0.211 134 402 554 307 598 620 416 409 6;
  • 16) 0.211 134 402 554 307 598 620 416 409 6 × 2 = 0 + 0.422 268 805 108 615 197 240 832 819 2;
  • 17) 0.422 268 805 108 615 197 240 832 819 2 × 2 = 0 + 0.844 537 610 217 230 394 481 665 638 4;
  • 18) 0.844 537 610 217 230 394 481 665 638 4 × 2 = 1 + 0.689 075 220 434 460 788 963 331 276 8;
  • 19) 0.689 075 220 434 460 788 963 331 276 8 × 2 = 1 + 0.378 150 440 868 921 577 926 662 553 6;
  • 20) 0.378 150 440 868 921 577 926 662 553 6 × 2 = 0 + 0.756 300 881 737 843 155 853 325 107 2;
  • 21) 0.756 300 881 737 843 155 853 325 107 2 × 2 = 1 + 0.512 601 763 475 686 311 706 650 214 4;
  • 22) 0.512 601 763 475 686 311 706 650 214 4 × 2 = 1 + 0.025 203 526 951 372 623 413 300 428 8;
  • 23) 0.025 203 526 951 372 623 413 300 428 8 × 2 = 0 + 0.050 407 053 902 745 246 826 600 857 6;
  • 24) 0.050 407 053 902 745 246 826 600 857 6 × 2 = 0 + 0.100 814 107 805 490 493 653 201 715 2;
  • 25) 0.100 814 107 805 490 493 653 201 715 2 × 2 = 0 + 0.201 628 215 610 980 987 306 403 430 4;
  • 26) 0.201 628 215 610 980 987 306 403 430 4 × 2 = 0 + 0.403 256 431 221 961 974 612 806 860 8;
  • 27) 0.403 256 431 221 961 974 612 806 860 8 × 2 = 0 + 0.806 512 862 443 923 949 225 613 721 6;
  • 28) 0.806 512 862 443 923 949 225 613 721 6 × 2 = 1 + 0.613 025 724 887 847 898 451 227 443 2;
  • 29) 0.613 025 724 887 847 898 451 227 443 2 × 2 = 1 + 0.226 051 449 775 695 796 902 454 886 4;
  • 30) 0.226 051 449 775 695 796 902 454 886 4 × 2 = 0 + 0.452 102 899 551 391 593 804 909 772 8;
  • 31) 0.452 102 899 551 391 593 804 909 772 8 × 2 = 0 + 0.904 205 799 102 783 187 609 819 545 6;
  • 32) 0.904 205 799 102 783 187 609 819 545 6 × 2 = 1 + 0.808 411 598 205 566 375 219 639 091 2;
  • 33) 0.808 411 598 205 566 375 219 639 091 2 × 2 = 1 + 0.616 823 196 411 132 750 439 278 182 4;
  • 34) 0.616 823 196 411 132 750 439 278 182 4 × 2 = 1 + 0.233 646 392 822 265 500 878 556 364 8;
  • 35) 0.233 646 392 822 265 500 878 556 364 8 × 2 = 0 + 0.467 292 785 644 531 001 757 112 729 6;
  • 36) 0.467 292 785 644 531 001 757 112 729 6 × 2 = 0 + 0.934 585 571 289 062 003 514 225 459 2;
  • 37) 0.934 585 571 289 062 003 514 225 459 2 × 2 = 1 + 0.869 171 142 578 124 007 028 450 918 4;
  • 38) 0.869 171 142 578 124 007 028 450 918 4 × 2 = 1 + 0.738 342 285 156 248 014 056 901 836 8;
  • 39) 0.738 342 285 156 248 014 056 901 836 8 × 2 = 1 + 0.476 684 570 312 496 028 113 803 673 6;
  • 40) 0.476 684 570 312 496 028 113 803 673 6 × 2 = 0 + 0.953 369 140 624 992 056 227 607 347 2;
  • 41) 0.953 369 140 624 992 056 227 607 347 2 × 2 = 1 + 0.906 738 281 249 984 112 455 214 694 4;
  • 42) 0.906 738 281 249 984 112 455 214 694 4 × 2 = 1 + 0.813 476 562 499 968 224 910 429 388 8;
  • 43) 0.813 476 562 499 968 224 910 429 388 8 × 2 = 1 + 0.626 953 124 999 936 449 820 858 777 6;
  • 44) 0.626 953 124 999 936 449 820 858 777 6 × 2 = 1 + 0.253 906 249 999 872 899 641 717 555 2;
  • 45) 0.253 906 249 999 872 899 641 717 555 2 × 2 = 0 + 0.507 812 499 999 745 799 283 435 110 4;
  • 46) 0.507 812 499 999 745 799 283 435 110 4 × 2 = 1 + 0.015 624 999 999 491 598 566 870 220 8;
  • 47) 0.015 624 999 999 491 598 566 870 220 8 × 2 = 0 + 0.031 249 999 998 983 197 133 740 441 6;
  • 48) 0.031 249 999 998 983 197 133 740 441 6 × 2 = 0 + 0.062 499 999 997 966 394 267 480 883 2;
  • 49) 0.062 499 999 997 966 394 267 480 883 2 × 2 = 0 + 0.124 999 999 995 932 788 534 961 766 4;
  • 50) 0.124 999 999 995 932 788 534 961 766 4 × 2 = 0 + 0.249 999 999 991 865 577 069 923 532 8;
  • 51) 0.249 999 999 991 865 577 069 923 532 8 × 2 = 0 + 0.499 999 999 983 731 154 139 847 065 6;
  • 52) 0.499 999 999 983 731 154 139 847 065 6 × 2 = 0 + 0.999 999 999 967 462 308 279 694 131 2;
  • 53) 0.999 999 999 967 462 308 279 694 131 2 × 2 = 1 + 0.999 999 999 934 924 616 559 388 262 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:


0.745 459 324 169 999 826 281 696 179 7(10) =


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

5. Positive number before normalization:

1.745 459 324 169 999 826 281 696 179 7(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:


1.745 459 324 169 999 826 281 696 179 7(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 1.745 459 324 169 999 826 281 696 179 7 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