-0.105 000 099 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal -0.105 000 099(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
-0.105 000 099(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:

|-0.105 000 099| = 0.105 000 099


2. First, convert to binary (in base 2) the integer part: 0.
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;
  • 0 ÷ 2 = 0 + 0;

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.

0(10) =


0(2)


4. Convert to binary (base 2) the fractional part: 0.105 000 099.

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) 0.105 000 099 × 2 = 0 + 0.210 000 198;
  • 2) 0.210 000 198 × 2 = 0 + 0.420 000 396;
  • 3) 0.420 000 396 × 2 = 0 + 0.840 000 792;
  • 4) 0.840 000 792 × 2 = 1 + 0.680 001 584;
  • 5) 0.680 001 584 × 2 = 1 + 0.360 003 168;
  • 6) 0.360 003 168 × 2 = 0 + 0.720 006 336;
  • 7) 0.720 006 336 × 2 = 1 + 0.440 012 672;
  • 8) 0.440 012 672 × 2 = 0 + 0.880 025 344;
  • 9) 0.880 025 344 × 2 = 1 + 0.760 050 688;
  • 10) 0.760 050 688 × 2 = 1 + 0.520 101 376;
  • 11) 0.520 101 376 × 2 = 1 + 0.040 202 752;
  • 12) 0.040 202 752 × 2 = 0 + 0.080 405 504;
  • 13) 0.080 405 504 × 2 = 0 + 0.160 811 008;
  • 14) 0.160 811 008 × 2 = 0 + 0.321 622 016;
  • 15) 0.321 622 016 × 2 = 0 + 0.643 244 032;
  • 16) 0.643 244 032 × 2 = 1 + 0.286 488 064;
  • 17) 0.286 488 064 × 2 = 0 + 0.572 976 128;
  • 18) 0.572 976 128 × 2 = 1 + 0.145 952 256;
  • 19) 0.145 952 256 × 2 = 0 + 0.291 904 512;
  • 20) 0.291 904 512 × 2 = 0 + 0.583 809 024;
  • 21) 0.583 809 024 × 2 = 1 + 0.167 618 048;
  • 22) 0.167 618 048 × 2 = 0 + 0.335 236 096;
  • 23) 0.335 236 096 × 2 = 0 + 0.670 472 192;
  • 24) 0.670 472 192 × 2 = 1 + 0.340 944 384;
  • 25) 0.340 944 384 × 2 = 0 + 0.681 888 768;
  • 26) 0.681 888 768 × 2 = 1 + 0.363 777 536;
  • 27) 0.363 777 536 × 2 = 0 + 0.727 555 072;
  • 28) 0.727 555 072 × 2 = 1 + 0.455 110 144;
  • 29) 0.455 110 144 × 2 = 0 + 0.910 220 288;
  • 30) 0.910 220 288 × 2 = 1 + 0.820 440 576;
  • 31) 0.820 440 576 × 2 = 1 + 0.640 881 152;
  • 32) 0.640 881 152 × 2 = 1 + 0.281 762 304;
  • 33) 0.281 762 304 × 2 = 0 + 0.563 524 608;
  • 34) 0.563 524 608 × 2 = 1 + 0.127 049 216;
  • 35) 0.127 049 216 × 2 = 0 + 0.254 098 432;
  • 36) 0.254 098 432 × 2 = 0 + 0.508 196 864;
  • 37) 0.508 196 864 × 2 = 1 + 0.016 393 728;
  • 38) 0.016 393 728 × 2 = 0 + 0.032 787 456;
  • 39) 0.032 787 456 × 2 = 0 + 0.065 574 912;
  • 40) 0.065 574 912 × 2 = 0 + 0.131 149 824;
  • 41) 0.131 149 824 × 2 = 0 + 0.262 299 648;
  • 42) 0.262 299 648 × 2 = 0 + 0.524 599 296;
  • 43) 0.524 599 296 × 2 = 1 + 0.049 198 592;
  • 44) 0.049 198 592 × 2 = 0 + 0.098 397 184;
  • 45) 0.098 397 184 × 2 = 0 + 0.196 794 368;
  • 46) 0.196 794 368 × 2 = 0 + 0.393 588 736;
  • 47) 0.393 588 736 × 2 = 0 + 0.787 177 472;
  • 48) 0.787 177 472 × 2 = 1 + 0.574 354 944;
  • 49) 0.574 354 944 × 2 = 1 + 0.148 709 888;
  • 50) 0.148 709 888 × 2 = 0 + 0.297 419 776;
  • 51) 0.297 419 776 × 2 = 0 + 0.594 839 552;
  • 52) 0.594 839 552 × 2 = 1 + 0.189 679 104;
  • 53) 0.189 679 104 × 2 = 0 + 0.379 358 208;
  • 54) 0.379 358 208 × 2 = 0 + 0.758 716 416;
  • 55) 0.758 716 416 × 2 = 1 + 0.517 432 832;
  • 56) 0.517 432 832 × 2 = 1 + 0.034 865 664;

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:


0.105 000 099(10) =


0.0001 1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011(2)

6. Positive number before normalization:

0.105 000 099(10) =


0.0001 1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011(2)

7. Normalize the binary representation of the number.

Shift the decimal mark 4 positions to the right, so that only one non zero digit remains to the left of it:


0.105 000 099(10) =


0.0001 1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011(2) =


0.0001 1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011(2) × 20 =


1.1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011(2) × 2-4


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):
1.1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011


9. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


-4 + 2(11-1) - 1 =


(-4 + 1 023)(10) =


1 019(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;
  • 1 019 ÷ 2 = 509 + 1;
  • 509 ÷ 2 = 254 + 1;
  • 254 ÷ 2 = 127 + 0;
  • 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;

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) =


1019(10) =


011 1111 1011(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, only if necessary (not the case here).


Mantissa (normalized) =


1. 1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011 =


1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011


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) =
011 1111 1011


Mantissa (52 bits) =
1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011


Decimal number -0.105 000 099 converted to 64 bit double precision IEEE 754 binary floating point representation:

1 - 011 1111 1011 - 1010 1110 0001 0100 1001 0101 0111 0100 1000 0010 0001 1001 0011


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