32 Bit IEEE 754 Binary to Float: Convert 0 - 1111 1101 - 000 0000 0000 0000 0000 0001, Number Written in 32 Bit Single Precision IEEE 754 Binary Floating Point Standard Representation, to a Base Ten Decimal System Float
0 - 1111 1101 - 000 0000 0000 0000 0000 0001: 32 bit single precision IEEE 754 binary floating point standard representation number converted to a base ten decimal system float
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 8 bits contain the exponent:
1111 1101
The last 23 bits contain the mantissa:
000 0000 0000 0000 0000 0001
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
1111 1101(2) =
1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 0 × 21 + 1 × 20 =
128 + 64 + 32 + 16 + 8 + 4 + 0 + 1 =
128 + 64 + 32 + 16 + 8 + 4 + 1 =
253(10)
3. Adjust the exponent.
Subtract the excess bits: 2(8 - 1) - 1 = 127,
that is due to the 8 bit excess/bias notation.
The exponent, adjusted = 253 - 127 = 126
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).
000 0000 0000 0000 0000 0001(2) =
0 × 2-1 + 0 × 2-2 + 0 × 2-3 + 0 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 0 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 0 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 1 × 2-23 =
0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 119 209 289 550 781 25 =
0.000 000 119 209 289 550 781 25 =
0.000 000 119 209 289 550 781 25(10)
5. Put all the numbers into expression to calculate the single precision floating point decimal value:
(-1)Sign × (1 + Mantissa) × 2(Adjusted exponent) =
(-1)0 × (1 + 0.000 000 119 209 289 550 781 25) × 2126 =
1.000 000 119 209 289 550 781 25 × 2126 =
85 070 601 871 439 417 691 678 863 831 567 695 872
0 - 1111 1101 - 000 0000 0000 0000 0000 0001 converted from a 32 bit single precision IEEE 754 binary floating point standard representation number to a decimal system number, written in base ten (float) = 85 070 601 871 439 417 691 678 863 831 567 695 872(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.