-284.011 100 000 001 109 656 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal -284.011 100 000 001 109 656(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
-284.011 100 000 001 109 656(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:

|-284.011 100 000 001 109 656| = 284.011 100 000 001 109 656


2. First, convert to binary (in base 2) the integer part: 284.
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;
  • 284 ÷ 2 = 142 + 0;
  • 142 ÷ 2 = 71 + 0;
  • 71 ÷ 2 = 35 + 1;
  • 35 ÷ 2 = 17 + 1;
  • 17 ÷ 2 = 8 + 1;
  • 8 ÷ 2 = 4 + 0;
  • 4 ÷ 2 = 2 + 0;
  • 2 ÷ 2 = 1 + 0;
  • 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.

284(10) =


1 0001 1100(2)


4. Convert to binary (base 2) the fractional part: 0.011 100 000 001 109 656.

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) 0.011 100 000 001 109 656 × 2 = 0 + 0.022 200 000 002 219 312;
  • 2) 0.022 200 000 002 219 312 × 2 = 0 + 0.044 400 000 004 438 624;
  • 3) 0.044 400 000 004 438 624 × 2 = 0 + 0.088 800 000 008 877 248;
  • 4) 0.088 800 000 008 877 248 × 2 = 0 + 0.177 600 000 017 754 496;
  • 5) 0.177 600 000 017 754 496 × 2 = 0 + 0.355 200 000 035 508 992;
  • 6) 0.355 200 000 035 508 992 × 2 = 0 + 0.710 400 000 071 017 984;
  • 7) 0.710 400 000 071 017 984 × 2 = 1 + 0.420 800 000 142 035 968;
  • 8) 0.420 800 000 142 035 968 × 2 = 0 + 0.841 600 000 284 071 936;
  • 9) 0.841 600 000 284 071 936 × 2 = 1 + 0.683 200 000 568 143 872;
  • 10) 0.683 200 000 568 143 872 × 2 = 1 + 0.366 400 001 136 287 744;
  • 11) 0.366 400 001 136 287 744 × 2 = 0 + 0.732 800 002 272 575 488;
  • 12) 0.732 800 002 272 575 488 × 2 = 1 + 0.465 600 004 545 150 976;
  • 13) 0.465 600 004 545 150 976 × 2 = 0 + 0.931 200 009 090 301 952;
  • 14) 0.931 200 009 090 301 952 × 2 = 1 + 0.862 400 018 180 603 904;
  • 15) 0.862 400 018 180 603 904 × 2 = 1 + 0.724 800 036 361 207 808;
  • 16) 0.724 800 036 361 207 808 × 2 = 1 + 0.449 600 072 722 415 616;
  • 17) 0.449 600 072 722 415 616 × 2 = 0 + 0.899 200 145 444 831 232;
  • 18) 0.899 200 145 444 831 232 × 2 = 1 + 0.798 400 290 889 662 464;
  • 19) 0.798 400 290 889 662 464 × 2 = 1 + 0.596 800 581 779 324 928;
  • 20) 0.596 800 581 779 324 928 × 2 = 1 + 0.193 601 163 558 649 856;
  • 21) 0.193 601 163 558 649 856 × 2 = 0 + 0.387 202 327 117 299 712;
  • 22) 0.387 202 327 117 299 712 × 2 = 0 + 0.774 404 654 234 599 424;
  • 23) 0.774 404 654 234 599 424 × 2 = 1 + 0.548 809 308 469 198 848;
  • 24) 0.548 809 308 469 198 848 × 2 = 1 + 0.097 618 616 938 397 696;
  • 25) 0.097 618 616 938 397 696 × 2 = 0 + 0.195 237 233 876 795 392;
  • 26) 0.195 237 233 876 795 392 × 2 = 0 + 0.390 474 467 753 590 784;
  • 27) 0.390 474 467 753 590 784 × 2 = 0 + 0.780 948 935 507 181 568;
  • 28) 0.780 948 935 507 181 568 × 2 = 1 + 0.561 897 871 014 363 136;
  • 29) 0.561 897 871 014 363 136 × 2 = 1 + 0.123 795 742 028 726 272;
  • 30) 0.123 795 742 028 726 272 × 2 = 0 + 0.247 591 484 057 452 544;
  • 31) 0.247 591 484 057 452 544 × 2 = 0 + 0.495 182 968 114 905 088;
  • 32) 0.495 182 968 114 905 088 × 2 = 0 + 0.990 365 936 229 810 176;
  • 33) 0.990 365 936 229 810 176 × 2 = 1 + 0.980 731 872 459 620 352;
  • 34) 0.980 731 872 459 620 352 × 2 = 1 + 0.961 463 744 919 240 704;
  • 35) 0.961 463 744 919 240 704 × 2 = 1 + 0.922 927 489 838 481 408;
  • 36) 0.922 927 489 838 481 408 × 2 = 1 + 0.845 854 979 676 962 816;
  • 37) 0.845 854 979 676 962 816 × 2 = 1 + 0.691 709 959 353 925 632;
  • 38) 0.691 709 959 353 925 632 × 2 = 1 + 0.383 419 918 707 851 264;
  • 39) 0.383 419 918 707 851 264 × 2 = 0 + 0.766 839 837 415 702 528;
  • 40) 0.766 839 837 415 702 528 × 2 = 1 + 0.533 679 674 831 405 056;
  • 41) 0.533 679 674 831 405 056 × 2 = 1 + 0.067 359 349 662 810 112;
  • 42) 0.067 359 349 662 810 112 × 2 = 0 + 0.134 718 699 325 620 224;
  • 43) 0.134 718 699 325 620 224 × 2 = 0 + 0.269 437 398 651 240 448;
  • 44) 0.269 437 398 651 240 448 × 2 = 0 + 0.538 874 797 302 480 896;
  • 45) 0.538 874 797 302 480 896 × 2 = 1 + 0.077 749 594 604 961 792;
  • 46) 0.077 749 594 604 961 792 × 2 = 0 + 0.155 499 189 209 923 584;
  • 47) 0.155 499 189 209 923 584 × 2 = 0 + 0.310 998 378 419 847 168;
  • 48) 0.310 998 378 419 847 168 × 2 = 0 + 0.621 996 756 839 694 336;
  • 49) 0.621 996 756 839 694 336 × 2 = 1 + 0.243 993 513 679 388 672;
  • 50) 0.243 993 513 679 388 672 × 2 = 0 + 0.487 987 027 358 777 344;
  • 51) 0.487 987 027 358 777 344 × 2 = 0 + 0.975 974 054 717 554 688;
  • 52) 0.975 974 054 717 554 688 × 2 = 1 + 0.951 948 109 435 109 376;
  • 53) 0.951 948 109 435 109 376 × 2 = 1 + 0.903 896 218 870 218 752;

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:


0.011 100 000 001 109 656(10) =


0.0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000 1000 1001 1(2)

6. Positive number before normalization:

284.011 100 000 001 109 656(10) =


1 0001 1100.0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000 1000 1001 1(2)

7. Normalize the binary representation of the number.

Shift the decimal mark 8 positions to the left, so that only one non zero digit remains to the left of it:


284.011 100 000 001 109 656(10) =


1 0001 1100.0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000 1000 1001 1(2) =


1 0001 1100.0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000 1000 1001 1(2) × 20 =


1.0001 1100 0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000 1000 1001 1(2) × 28


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): 8


Mantissa (not normalized):
1.0001 1100 0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000 1000 1001 1


9. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


8 + 2(11-1) - 1 =


(8 + 1 023)(10) =


1 031(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;
  • 1 031 ÷ 2 = 515 + 1;
  • 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) =


1031(10) =


100 0000 0111(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. 0001 1100 0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000 1 0001 0011 =


0001 1100 0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000


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 0111


Mantissa (52 bits) =
0001 1100 0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000


Decimal number -284.011 100 000 001 109 656 converted to 64 bit double precision IEEE 754 binary floating point representation:

1 - 100 0000 0111 - 0001 1100 0000 0010 1101 0111 0111 0011 0001 1000 1111 1101 1000


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