-199.219 999 999 999 998 863 131 622 783 839 694 1 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal -199.219 999 999 999 998 863 131 622 783 839 694 1(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
-199.219 999 999 999 998 863 131 622 783 839 694 1(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. Start with the positive version of the number:

|-199.219 999 999 999 998 863 131 622 783 839 694 1| = 199.219 999 999 999 998 863 131 622 783 839 694 1


2. First, convert to binary (in base 2) the integer part: 199.
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;
  • 199 ÷ 2 = 99 + 1;
  • 99 ÷ 2 = 49 + 1;
  • 49 ÷ 2 = 24 + 1;
  • 24 ÷ 2 = 12 + 0;
  • 12 ÷ 2 = 6 + 0;
  • 6 ÷ 2 = 3 + 0;
  • 3 ÷ 2 = 1 + 1;
  • 1 ÷ 2 = 0 + 1;

3. 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.

199(10) =


1100 0111(2)


4. Convert to binary (base 2) the fractional part: 0.219 999 999 999 998 863 131 622 783 839 694 1.

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) 0.219 999 999 999 998 863 131 622 783 839 694 1 × 2 = 0 + 0.439 999 999 999 997 726 263 245 567 679 388 2;
  • 2) 0.439 999 999 999 997 726 263 245 567 679 388 2 × 2 = 0 + 0.879 999 999 999 995 452 526 491 135 358 776 4;
  • 3) 0.879 999 999 999 995 452 526 491 135 358 776 4 × 2 = 1 + 0.759 999 999 999 990 905 052 982 270 717 552 8;
  • 4) 0.759 999 999 999 990 905 052 982 270 717 552 8 × 2 = 1 + 0.519 999 999 999 981 810 105 964 541 435 105 6;
  • 5) 0.519 999 999 999 981 810 105 964 541 435 105 6 × 2 = 1 + 0.039 999 999 999 963 620 211 929 082 870 211 2;
  • 6) 0.039 999 999 999 963 620 211 929 082 870 211 2 × 2 = 0 + 0.079 999 999 999 927 240 423 858 165 740 422 4;
  • 7) 0.079 999 999 999 927 240 423 858 165 740 422 4 × 2 = 0 + 0.159 999 999 999 854 480 847 716 331 480 844 8;
  • 8) 0.159 999 999 999 854 480 847 716 331 480 844 8 × 2 = 0 + 0.319 999 999 999 708 961 695 432 662 961 689 6;
  • 9) 0.319 999 999 999 708 961 695 432 662 961 689 6 × 2 = 0 + 0.639 999 999 999 417 923 390 865 325 923 379 2;
  • 10) 0.639 999 999 999 417 923 390 865 325 923 379 2 × 2 = 1 + 0.279 999 999 998 835 846 781 730 651 846 758 4;
  • 11) 0.279 999 999 998 835 846 781 730 651 846 758 4 × 2 = 0 + 0.559 999 999 997 671 693 563 461 303 693 516 8;
  • 12) 0.559 999 999 997 671 693 563 461 303 693 516 8 × 2 = 1 + 0.119 999 999 995 343 387 126 922 607 387 033 6;
  • 13) 0.119 999 999 995 343 387 126 922 607 387 033 6 × 2 = 0 + 0.239 999 999 990 686 774 253 845 214 774 067 2;
  • 14) 0.239 999 999 990 686 774 253 845 214 774 067 2 × 2 = 0 + 0.479 999 999 981 373 548 507 690 429 548 134 4;
  • 15) 0.479 999 999 981 373 548 507 690 429 548 134 4 × 2 = 0 + 0.959 999 999 962 747 097 015 380 859 096 268 8;
  • 16) 0.959 999 999 962 747 097 015 380 859 096 268 8 × 2 = 1 + 0.919 999 999 925 494 194 030 761 718 192 537 6;
  • 17) 0.919 999 999 925 494 194 030 761 718 192 537 6 × 2 = 1 + 0.839 999 999 850 988 388 061 523 436 385 075 2;
  • 18) 0.839 999 999 850 988 388 061 523 436 385 075 2 × 2 = 1 + 0.679 999 999 701 976 776 123 046 872 770 150 4;
  • 19) 0.679 999 999 701 976 776 123 046 872 770 150 4 × 2 = 1 + 0.359 999 999 403 953 552 246 093 745 540 300 8;
  • 20) 0.359 999 999 403 953 552 246 093 745 540 300 8 × 2 = 0 + 0.719 999 998 807 907 104 492 187 491 080 601 6;
  • 21) 0.719 999 998 807 907 104 492 187 491 080 601 6 × 2 = 1 + 0.439 999 997 615 814 208 984 374 982 161 203 2;
  • 22) 0.439 999 997 615 814 208 984 374 982 161 203 2 × 2 = 0 + 0.879 999 995 231 628 417 968 749 964 322 406 4;
  • 23) 0.879 999 995 231 628 417 968 749 964 322 406 4 × 2 = 1 + 0.759 999 990 463 256 835 937 499 928 644 812 8;
  • 24) 0.759 999 990 463 256 835 937 499 928 644 812 8 × 2 = 1 + 0.519 999 980 926 513 671 874 999 857 289 625 6;
  • 25) 0.519 999 980 926 513 671 874 999 857 289 625 6 × 2 = 1 + 0.039 999 961 853 027 343 749 999 714 579 251 2;
  • 26) 0.039 999 961 853 027 343 749 999 714 579 251 2 × 2 = 0 + 0.079 999 923 706 054 687 499 999 429 158 502 4;
  • 27) 0.079 999 923 706 054 687 499 999 429 158 502 4 × 2 = 0 + 0.159 999 847 412 109 374 999 998 858 317 004 8;
  • 28) 0.159 999 847 412 109 374 999 998 858 317 004 8 × 2 = 0 + 0.319 999 694 824 218 749 999 997 716 634 009 6;
  • 29) 0.319 999 694 824 218 749 999 997 716 634 009 6 × 2 = 0 + 0.639 999 389 648 437 499 999 995 433 268 019 2;
  • 30) 0.639 999 389 648 437 499 999 995 433 268 019 2 × 2 = 1 + 0.279 998 779 296 874 999 999 990 866 536 038 4;
  • 31) 0.279 998 779 296 874 999 999 990 866 536 038 4 × 2 = 0 + 0.559 997 558 593 749 999 999 981 733 072 076 8;
  • 32) 0.559 997 558 593 749 999 999 981 733 072 076 8 × 2 = 1 + 0.119 995 117 187 499 999 999 963 466 144 153 6;
  • 33) 0.119 995 117 187 499 999 999 963 466 144 153 6 × 2 = 0 + 0.239 990 234 374 999 999 999 926 932 288 307 2;
  • 34) 0.239 990 234 374 999 999 999 926 932 288 307 2 × 2 = 0 + 0.479 980 468 749 999 999 999 853 864 576 614 4;
  • 35) 0.479 980 468 749 999 999 999 853 864 576 614 4 × 2 = 0 + 0.959 960 937 499 999 999 999 707 729 153 228 8;
  • 36) 0.959 960 937 499 999 999 999 707 729 153 228 8 × 2 = 1 + 0.919 921 874 999 999 999 999 415 458 306 457 6;
  • 37) 0.919 921 874 999 999 999 999 415 458 306 457 6 × 2 = 1 + 0.839 843 749 999 999 999 998 830 916 612 915 2;
  • 38) 0.839 843 749 999 999 999 998 830 916 612 915 2 × 2 = 1 + 0.679 687 499 999 999 999 997 661 833 225 830 4;
  • 39) 0.679 687 499 999 999 999 997 661 833 225 830 4 × 2 = 1 + 0.359 374 999 999 999 999 995 323 666 451 660 8;
  • 40) 0.359 374 999 999 999 999 995 323 666 451 660 8 × 2 = 0 + 0.718 749 999 999 999 999 990 647 332 903 321 6;
  • 41) 0.718 749 999 999 999 999 990 647 332 903 321 6 × 2 = 1 + 0.437 499 999 999 999 999 981 294 665 806 643 2;
  • 42) 0.437 499 999 999 999 999 981 294 665 806 643 2 × 2 = 0 + 0.874 999 999 999 999 999 962 589 331 613 286 4;
  • 43) 0.874 999 999 999 999 999 962 589 331 613 286 4 × 2 = 1 + 0.749 999 999 999 999 999 925 178 663 226 572 8;
  • 44) 0.749 999 999 999 999 999 925 178 663 226 572 8 × 2 = 1 + 0.499 999 999 999 999 999 850 357 326 453 145 6;
  • 45) 0.499 999 999 999 999 999 850 357 326 453 145 6 × 2 = 0 + 0.999 999 999 999 999 999 700 714 652 906 291 2;
  • 46) 0.999 999 999 999 999 999 700 714 652 906 291 2 × 2 = 1 + 0.999 999 999 999 999 999 401 429 305 812 582 4;
  • 47) 0.999 999 999 999 999 999 401 429 305 812 582 4 × 2 = 1 + 0.999 999 999 999 999 998 802 858 611 625 164 8;
  • 48) 0.999 999 999 999 999 998 802 858 611 625 164 8 × 2 = 1 + 0.999 999 999 999 999 997 605 717 223 250 329 6;
  • 49) 0.999 999 999 999 999 997 605 717 223 250 329 6 × 2 = 1 + 0.999 999 999 999 999 995 211 434 446 500 659 2;
  • 50) 0.999 999 999 999 999 995 211 434 446 500 659 2 × 2 = 1 + 0.999 999 999 999 999 990 422 868 893 001 318 4;
  • 51) 0.999 999 999 999 999 990 422 868 893 001 318 4 × 2 = 1 + 0.999 999 999 999 999 980 845 737 786 002 636 8;
  • 52) 0.999 999 999 999 999 980 845 737 786 002 636 8 × 2 = 1 + 0.999 999 999 999 999 961 691 475 572 005 273 6;
  • 53) 0.999 999 999 999 999 961 691 475 572 005 273 6 × 2 = 1 + 0.999 999 999 999 999 923 382 951 144 010 547 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).


5. 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:


0.219 999 999 999 998 863 131 622 783 839 694 1(10) =


0.0011 1000 0101 0001 1110 1011 1000 0101 0001 1110 1011 0111 1111 1(2)

6. Positive number before normalization:

199.219 999 999 999 998 863 131 622 783 839 694 1(10) =


1100 0111.0011 1000 0101 0001 1110 1011 1000 0101 0001 1110 1011 0111 1111 1(2)

7. Normalize the binary representation of the number.

Shift the decimal mark 7 positions to the left, so that only one non zero digit remains to the left of it:


199.219 999 999 999 998 863 131 622 783 839 694 1(10) =


1100 0111.0011 1000 0101 0001 1110 1011 1000 0101 0001 1110 1011 0111 1111 1(2) =


1100 0111.0011 1000 0101 0001 1110 1011 1000 0101 0001 1110 1011 0111 1111 1(2) × 20 =


1.1000 1110 0111 0000 1010 0011 1101 0111 0000 1010 0011 1101 0110 1111 1111(2) × 27


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): 7


Mantissa (not normalized):
1.1000 1110 0111 0000 1010 0011 1101 0111 0000 1010 0011 1101 0110 1111 1111


9. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


7 + 2(11-1) - 1 =


(7 + 1 023)(10) =


1 030(10)


10. 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;
  • 1 030 ÷ 2 = 515 + 0;
  • 515 ÷ 2 = 257 + 1;
  • 257 ÷ 2 = 128 + 1;
  • 128 ÷ 2 = 64 + 0;
  • 64 ÷ 2 = 32 + 0;
  • 32 ÷ 2 = 16 + 0;
  • 16 ÷ 2 = 8 + 0;
  • 8 ÷ 2 = 4 + 0;
  • 4 ÷ 2 = 2 + 0;
  • 2 ÷ 2 = 1 + 0;
  • 1 ÷ 2 = 0 + 1;

11. Construct the base 2 representation of the adjusted exponent.

Take all the remainders starting from the bottom of the list constructed above.


Exponent (adjusted) =


1030(10) =


100 0000 0110(2)


12. 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. 1000 1110 0111 0000 1010 0011 1101 0111 0000 1010 0011 1101 0110 1111 1111 =


1000 1110 0111 0000 1010 0011 1101 0111 0000 1010 0011 1101 0110


13. The three elements that make up the number's 64 bit double precision IEEE 754 binary floating point representation:

Sign (1 bit) =
1 (a negative number)


Exponent (11 bits) =
100 0000 0110


Mantissa (52 bits) =
1000 1110 0111 0000 1010 0011 1101 0111 0000 1010 0011 1101 0110


Decimal number -199.219 999 999 999 998 863 131 622 783 839 694 1 converted to 64 bit double precision IEEE 754 binary floating point representation:

1 - 100 0000 0110 - 1000 1110 0111 0000 1010 0011 1101 0111 0000 1010 0011 1101 0110

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