64 Bit IEEE 754 Binary to Double: Convert 0 - 100 0001 0101 - 1000 1000 1000 1000 1000 0000 0000 0000 0000 0000 0000 0011 0101, Number Written in 64 Bit Double Precision IEEE 754 Binary Floating Point Standard Representation, to a Base Ten Decimal System Double
0 - 100 0001 0101 - 1000 1000 1000 1000 1000 0000 0000 0000 0000 0000 0000 0011 0101: 64 bit double precision IEEE 754 binary floating point standard representation number converted to a base ten decimal system double
1. Identify the elements that make up the binary representation of the number:
The first bit (the leftmost) indicates the sign,
1 = negative, 0 = positive.
0
The next 11 bits contain the exponent:
100 0001 0101
The last 52 bits contain the mantissa:
1000 1000 1000 1000 1000 0000 0000 0000 0000 0000 0000 0011 0101
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
100 0001 0101(2) =
1 × 210 + 0 × 29 + 0 × 28 + 0 × 27 + 0 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 1 × 20 =
1,024 + 0 + 0 + 0 + 0 + 0 + 16 + 0 + 4 + 0 + 1 =
1,024 + 16 + 4 + 1 =
1,045(10)
3. Adjust the exponent.
Subtract the excess bits: 2(11 - 1) - 1 = 1023,
that is due to the 11 bit excess/bias notation.
The exponent, adjusted = 1,045 - 1023 = 22
4. Convert the mantissa from binary (from base 2) to decimal (in base 10).
The mantissa represents the fractional part of the number (what comes after the whole part of the number, separated from it by a comma).
1000 1000 1000 1000 1000 0000 0000 0000 0000 0000 0000 0011 0101(2) =
1 × 2-1 + 0 × 2-2 + 0 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 1 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 1 × 2-17 + 0 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 + 0 × 2-24 + 0 × 2-25 + 0 × 2-26 + 0 × 2-27 + 0 × 2-28 + 0 × 2-29 + 0 × 2-30 + 0 × 2-31 + 0 × 2-32 + 0 × 2-33 + 0 × 2-34 + 0 × 2-35 + 0 × 2-36 + 0 × 2-37 + 0 × 2-38 + 0 × 2-39 + 0 × 2-40 + 0 × 2-41 + 0 × 2-42 + 0 × 2-43 + 0 × 2-44 + 0 × 2-45 + 0 × 2-46 + 1 × 2-47 + 1 × 2-48 + 0 × 2-49 + 1 × 2-50 + 0 × 2-51 + 1 × 2-52 =
0.5 + 0 + 0 + 0 + 0.031 25 + 0 + 0 + 0 + 0.001 953 125 + 0 + 0 + 0 + 0.000 122 070 312 5 + 0 + 0 + 0 + 0.000 007 629 394 531 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 0 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.5 + 0.031 25 + 0.001 953 125 + 0.000 122 070 312 5 + 0.000 007 629 394 531 25 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.533 332 824 707 043 018 364 061 026 659 328 490 495 681 762 695 312 5(10)
5. Put all the numbers into expression to calculate the double precision floating point decimal value:
(-1)Sign × (1 + Mantissa) × 2(Adjusted exponent) =
(-1)0 × (1 + 0.533 332 824 707 043 018 364 061 026 659 328 490 495 681 762 695 312 5) × 222 =
1.533 332 824 707 043 018 364 061 026 659 328 490 495 681 762 695 312 5 × 222 = ...
= 6 431 264.000 000 049 360 096 454 620 361 328 125
0 - 100 0001 0101 - 1000 1000 1000 1000 1000 0000 0000 0000 0000 0000 0000 0011 0101 converted from a 64 bit double precision IEEE 754 binary floating point standard representation number to a decimal system number, written in base ten (double) = 6 431 264.000 000 049 360 096 454 620 361 328 125(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.