1.745 459 324 169 999 826 281 696 186 6 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 6(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 6(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 6.

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 6 × 2 = 1 + 0.490 918 648 339 999 652 563 392 373 2;
  • 2) 0.490 918 648 339 999 652 563 392 373 2 × 2 = 0 + 0.981 837 296 679 999 305 126 784 746 4;
  • 3) 0.981 837 296 679 999 305 126 784 746 4 × 2 = 1 + 0.963 674 593 359 998 610 253 569 492 8;
  • 4) 0.963 674 593 359 998 610 253 569 492 8 × 2 = 1 + 0.927 349 186 719 997 220 507 138 985 6;
  • 5) 0.927 349 186 719 997 220 507 138 985 6 × 2 = 1 + 0.854 698 373 439 994 441 014 277 971 2;
  • 6) 0.854 698 373 439 994 441 014 277 971 2 × 2 = 1 + 0.709 396 746 879 988 882 028 555 942 4;
  • 7) 0.709 396 746 879 988 882 028 555 942 4 × 2 = 1 + 0.418 793 493 759 977 764 057 111 884 8;
  • 8) 0.418 793 493 759 977 764 057 111 884 8 × 2 = 0 + 0.837 586 987 519 955 528 114 223 769 6;
  • 9) 0.837 586 987 519 955 528 114 223 769 6 × 2 = 1 + 0.675 173 975 039 911 056 228 447 539 2;
  • 10) 0.675 173 975 039 911 056 228 447 539 2 × 2 = 1 + 0.350 347 950 079 822 112 456 895 078 4;
  • 11) 0.350 347 950 079 822 112 456 895 078 4 × 2 = 0 + 0.700 695 900 159 644 224 913 790 156 8;
  • 12) 0.700 695 900 159 644 224 913 790 156 8 × 2 = 1 + 0.401 391 800 319 288 449 827 580 313 6;
  • 13) 0.401 391 800 319 288 449 827 580 313 6 × 2 = 0 + 0.802 783 600 638 576 899 655 160 627 2;
  • 14) 0.802 783 600 638 576 899 655 160 627 2 × 2 = 1 + 0.605 567 201 277 153 799 310 321 254 4;
  • 15) 0.605 567 201 277 153 799 310 321 254 4 × 2 = 1 + 0.211 134 402 554 307 598 620 642 508 8;
  • 16) 0.211 134 402 554 307 598 620 642 508 8 × 2 = 0 + 0.422 268 805 108 615 197 241 285 017 6;
  • 17) 0.422 268 805 108 615 197 241 285 017 6 × 2 = 0 + 0.844 537 610 217 230 394 482 570 035 2;
  • 18) 0.844 537 610 217 230 394 482 570 035 2 × 2 = 1 + 0.689 075 220 434 460 788 965 140 070 4;
  • 19) 0.689 075 220 434 460 788 965 140 070 4 × 2 = 1 + 0.378 150 440 868 921 577 930 280 140 8;
  • 20) 0.378 150 440 868 921 577 930 280 140 8 × 2 = 0 + 0.756 300 881 737 843 155 860 560 281 6;
  • 21) 0.756 300 881 737 843 155 860 560 281 6 × 2 = 1 + 0.512 601 763 475 686 311 721 120 563 2;
  • 22) 0.512 601 763 475 686 311 721 120 563 2 × 2 = 1 + 0.025 203 526 951 372 623 442 241 126 4;
  • 23) 0.025 203 526 951 372 623 442 241 126 4 × 2 = 0 + 0.050 407 053 902 745 246 884 482 252 8;
  • 24) 0.050 407 053 902 745 246 884 482 252 8 × 2 = 0 + 0.100 814 107 805 490 493 768 964 505 6;
  • 25) 0.100 814 107 805 490 493 768 964 505 6 × 2 = 0 + 0.201 628 215 610 980 987 537 929 011 2;
  • 26) 0.201 628 215 610 980 987 537 929 011 2 × 2 = 0 + 0.403 256 431 221 961 975 075 858 022 4;
  • 27) 0.403 256 431 221 961 975 075 858 022 4 × 2 = 0 + 0.806 512 862 443 923 950 151 716 044 8;
  • 28) 0.806 512 862 443 923 950 151 716 044 8 × 2 = 1 + 0.613 025 724 887 847 900 303 432 089 6;
  • 29) 0.613 025 724 887 847 900 303 432 089 6 × 2 = 1 + 0.226 051 449 775 695 800 606 864 179 2;
  • 30) 0.226 051 449 775 695 800 606 864 179 2 × 2 = 0 + 0.452 102 899 551 391 601 213 728 358 4;
  • 31) 0.452 102 899 551 391 601 213 728 358 4 × 2 = 0 + 0.904 205 799 102 783 202 427 456 716 8;
  • 32) 0.904 205 799 102 783 202 427 456 716 8 × 2 = 1 + 0.808 411 598 205 566 404 854 913 433 6;
  • 33) 0.808 411 598 205 566 404 854 913 433 6 × 2 = 1 + 0.616 823 196 411 132 809 709 826 867 2;
  • 34) 0.616 823 196 411 132 809 709 826 867 2 × 2 = 1 + 0.233 646 392 822 265 619 419 653 734 4;
  • 35) 0.233 646 392 822 265 619 419 653 734 4 × 2 = 0 + 0.467 292 785 644 531 238 839 307 468 8;
  • 36) 0.467 292 785 644 531 238 839 307 468 8 × 2 = 0 + 0.934 585 571 289 062 477 678 614 937 6;
  • 37) 0.934 585 571 289 062 477 678 614 937 6 × 2 = 1 + 0.869 171 142 578 124 955 357 229 875 2;
  • 38) 0.869 171 142 578 124 955 357 229 875 2 × 2 = 1 + 0.738 342 285 156 249 910 714 459 750 4;
  • 39) 0.738 342 285 156 249 910 714 459 750 4 × 2 = 1 + 0.476 684 570 312 499 821 428 919 500 8;
  • 40) 0.476 684 570 312 499 821 428 919 500 8 × 2 = 0 + 0.953 369 140 624 999 642 857 839 001 6;
  • 41) 0.953 369 140 624 999 642 857 839 001 6 × 2 = 1 + 0.906 738 281 249 999 285 715 678 003 2;
  • 42) 0.906 738 281 249 999 285 715 678 003 2 × 2 = 1 + 0.813 476 562 499 998 571 431 356 006 4;
  • 43) 0.813 476 562 499 998 571 431 356 006 4 × 2 = 1 + 0.626 953 124 999 997 142 862 712 012 8;
  • 44) 0.626 953 124 999 997 142 862 712 012 8 × 2 = 1 + 0.253 906 249 999 994 285 725 424 025 6;
  • 45) 0.253 906 249 999 994 285 725 424 025 6 × 2 = 0 + 0.507 812 499 999 988 571 450 848 051 2;
  • 46) 0.507 812 499 999 988 571 450 848 051 2 × 2 = 1 + 0.015 624 999 999 977 142 901 696 102 4;
  • 47) 0.015 624 999 999 977 142 901 696 102 4 × 2 = 0 + 0.031 249 999 999 954 285 803 392 204 8;
  • 48) 0.031 249 999 999 954 285 803 392 204 8 × 2 = 0 + 0.062 499 999 999 908 571 606 784 409 6;
  • 49) 0.062 499 999 999 908 571 606 784 409 6 × 2 = 0 + 0.124 999 999 999 817 143 213 568 819 2;
  • 50) 0.124 999 999 999 817 143 213 568 819 2 × 2 = 0 + 0.249 999 999 999 634 286 427 137 638 4;
  • 51) 0.249 999 999 999 634 286 427 137 638 4 × 2 = 0 + 0.499 999 999 999 268 572 854 275 276 8;
  • 52) 0.499 999 999 999 268 572 854 275 276 8 × 2 = 0 + 0.999 999 999 998 537 145 708 550 553 6;
  • 53) 0.999 999 999 998 537 145 708 550 553 6 × 2 = 1 + 0.999 999 999 997 074 291 417 101 107 2;

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 6(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 6(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 6(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 6 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