-0.000 282 381 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal -0.000 282 381(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
-0.000 282 381(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:

|-0.000 282 381| = 0.000 282 381


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: 0.000 282 381.

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) 0.000 282 381 × 2 = 0 + 0.000 564 762;
  • 2) 0.000 564 762 × 2 = 0 + 0.001 129 524;
  • 3) 0.001 129 524 × 2 = 0 + 0.002 259 048;
  • 4) 0.002 259 048 × 2 = 0 + 0.004 518 096;
  • 5) 0.004 518 096 × 2 = 0 + 0.009 036 192;
  • 6) 0.009 036 192 × 2 = 0 + 0.018 072 384;
  • 7) 0.018 072 384 × 2 = 0 + 0.036 144 768;
  • 8) 0.036 144 768 × 2 = 0 + 0.072 289 536;
  • 9) 0.072 289 536 × 2 = 0 + 0.144 579 072;
  • 10) 0.144 579 072 × 2 = 0 + 0.289 158 144;
  • 11) 0.289 158 144 × 2 = 0 + 0.578 316 288;
  • 12) 0.578 316 288 × 2 = 1 + 0.156 632 576;
  • 13) 0.156 632 576 × 2 = 0 + 0.313 265 152;
  • 14) 0.313 265 152 × 2 = 0 + 0.626 530 304;
  • 15) 0.626 530 304 × 2 = 1 + 0.253 060 608;
  • 16) 0.253 060 608 × 2 = 0 + 0.506 121 216;
  • 17) 0.506 121 216 × 2 = 1 + 0.012 242 432;
  • 18) 0.012 242 432 × 2 = 0 + 0.024 484 864;
  • 19) 0.024 484 864 × 2 = 0 + 0.048 969 728;
  • 20) 0.048 969 728 × 2 = 0 + 0.097 939 456;
  • 21) 0.097 939 456 × 2 = 0 + 0.195 878 912;
  • 22) 0.195 878 912 × 2 = 0 + 0.391 757 824;
  • 23) 0.391 757 824 × 2 = 0 + 0.783 515 648;
  • 24) 0.783 515 648 × 2 = 1 + 0.567 031 296;
  • 25) 0.567 031 296 × 2 = 1 + 0.134 062 592;
  • 26) 0.134 062 592 × 2 = 0 + 0.268 125 184;
  • 27) 0.268 125 184 × 2 = 0 + 0.536 250 368;
  • 28) 0.536 250 368 × 2 = 1 + 0.072 500 736;
  • 29) 0.072 500 736 × 2 = 0 + 0.145 001 472;
  • 30) 0.145 001 472 × 2 = 0 + 0.290 002 944;
  • 31) 0.290 002 944 × 2 = 0 + 0.580 005 888;
  • 32) 0.580 005 888 × 2 = 1 + 0.160 011 776;
  • 33) 0.160 011 776 × 2 = 0 + 0.320 023 552;
  • 34) 0.320 023 552 × 2 = 0 + 0.640 047 104;
  • 35) 0.640 047 104 × 2 = 1 + 0.280 094 208;
  • 36) 0.280 094 208 × 2 = 0 + 0.560 188 416;
  • 37) 0.560 188 416 × 2 = 1 + 0.120 376 832;
  • 38) 0.120 376 832 × 2 = 0 + 0.240 753 664;
  • 39) 0.240 753 664 × 2 = 0 + 0.481 507 328;
  • 40) 0.481 507 328 × 2 = 0 + 0.963 014 656;
  • 41) 0.963 014 656 × 2 = 1 + 0.926 029 312;
  • 42) 0.926 029 312 × 2 = 1 + 0.852 058 624;
  • 43) 0.852 058 624 × 2 = 1 + 0.704 117 248;
  • 44) 0.704 117 248 × 2 = 1 + 0.408 234 496;
  • 45) 0.408 234 496 × 2 = 0 + 0.816 468 992;
  • 46) 0.816 468 992 × 2 = 1 + 0.632 937 984;
  • 47) 0.632 937 984 × 2 = 1 + 0.265 875 968;
  • 48) 0.265 875 968 × 2 = 0 + 0.531 751 936;
  • 49) 0.531 751 936 × 2 = 1 + 0.063 503 872;
  • 50) 0.063 503 872 × 2 = 0 + 0.127 007 744;
  • 51) 0.127 007 744 × 2 = 0 + 0.254 015 488;
  • 52) 0.254 015 488 × 2 = 0 + 0.508 030 976;
  • 53) 0.508 030 976 × 2 = 1 + 0.016 061 952;
  • 54) 0.016 061 952 × 2 = 0 + 0.032 123 904;
  • 55) 0.032 123 904 × 2 = 0 + 0.064 247 808;
  • 56) 0.064 247 808 × 2 = 0 + 0.128 495 616;
  • 57) 0.128 495 616 × 2 = 0 + 0.256 991 232;
  • 58) 0.256 991 232 × 2 = 0 + 0.513 982 464;
  • 59) 0.513 982 464 × 2 = 1 + 0.027 964 928;
  • 60) 0.027 964 928 × 2 = 0 + 0.055 929 856;
  • 61) 0.055 929 856 × 2 = 0 + 0.111 859 712;
  • 62) 0.111 859 712 × 2 = 0 + 0.223 719 424;
  • 63) 0.223 719 424 × 2 = 0 + 0.447 438 848;
  • 64) 0.447 438 848 × 2 = 0 + 0.894 877 696;

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:


0.000 282 381(10) =


0.0000 0000 0001 0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000(2)

6. Positive number before normalization:

0.000 282 381(10) =


0.0000 0000 0001 0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000(2)

7. Normalize the binary representation of the number.

Shift the decimal mark 12 positions to the right, so that only one non zero digit remains to the left of it:


0.000 282 381(10) =


0.0000 0000 0001 0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000(2) =


0.0000 0000 0001 0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000(2) × 20 =


1.0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000(2) × 2-12


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): -12


Mantissa (not normalized):
1.0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000


9. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


-12 + 2(11-1) - 1 =


(-12 + 1 023)(10) =


1 011(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;
  • 1 011 ÷ 2 = 505 + 1;
  • 505 ÷ 2 = 252 + 1;
  • 252 ÷ 2 = 126 + 0;
  • 126 ÷ 2 = 63 + 0;
  • 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) =


1011(10) =


011 1111 0011(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. 0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000 =


0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000


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 0011


Mantissa (52 bits) =
0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 0000


Decimal number -0.000 282 381 converted to 64 bit double precision IEEE 754 binary floating point representation:

1 - 011 1111 0011 - 0010 1000 0001 1001 0001 0010 1000 1111 0110 1000 1000 0010 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