How to convert a signed binary two's complement:
1111 1101 1110 0111 0110 1100 1000 0110(2)
to an integer in decimal system (in base 10)
1. Is this a positive or a negative number?
In a signed binary two's complement, first bit (the leftmost) indicates the sign,
1 = negative, 0 = positive.
1111 1101 1110 0111 0110 1100 1000 0110 is the binary representation of a negative integer, on 32 bits (4 Bytes).
2. Get the binary representation in one's complement:
* Run this step only if the number is negative *
Subtract 1 from the binary initial number:
1111 1101 1110 0111 0110 1100 1000 0110 - 1 = 1111 1101 1110 0111 0110 1100 1000 0101
3. Get the binary representation of the positive (unsigned) number:
* Run this step only if the number is negative *
Flip all the bits in the signed binary one's complement representation (reverse the digits) - replace the bits set on 1 with 0s and the bits on 0 with 1s:
!(1111 1101 1110 0111 0110 1100 1000 0101) = 0000 0010 0001 1000 1001 0011 0111 1010
4. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
231
0 230
0 229
0 228
0 227
0 226
0 225
1 224
0 223
0 222
0 221
0 220
1 219
1 218
0 217
0 216
0 215
1 214
0 213
0 212
1 211
0 210
0 29
1 28
1 27
0 26
1 25
1 24
1 23
1 22
0 21
1 20
0
5. Multiply each bit by its corresponding power of 2 and add all the terms up:
0000 0010 0001 1000 1001 0011 0111 1010(2) =
(0 × 231 + 0 × 230 + 0 × 229 + 0 × 228 + 0 × 227 + 0 × 226 + 1 × 225 + 0 × 224 + 0 × 223 + 0 × 222 + 0 × 221 + 1 × 220 + 1 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 1 × 215 + 0 × 214 + 0 × 213 + 1 × 212 + 0 × 211 + 0 × 210 + 1 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 1 × 21 + 0 × 20)(10) =
(0 + 0 + 0 + 0 + 0 + 0 + 33 554 432 + 0 + 0 + 0 + 0 + 1 048 576 + 524 288 + 0 + 0 + 0 + 32 768 + 0 + 0 + 4 096 + 0 + 0 + 512 + 256 + 0 + 64 + 32 + 16 + 8 + 0 + 2 + 0)(10) =
(33 554 432 + 1 048 576 + 524 288 + 32 768 + 4 096 + 512 + 256 + 64 + 32 + 16 + 8 + 2)(10) =
35 165 050(10)
6. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1111 1101 1110 0111 0110 1100 1000 0110(2) = -35 165 050(10)
Conclusion:
Number 1111 1101 1110 0111 0110 1100 1000 0110(2) converted from signed binary two's complement representation to an integer in decimal system (in base 10):
1111 1101 1110 0111 0110 1100 1000 0110(2) = -35 165 050(10)
Spaces used to group digits: for binary, by 4; for decimal, by 3.
More operations of this kind:
Convert signed binary two's complement numbers to decimal system (base ten) integers
Entered binary number length must be: 2, 4, 8, 16, 32, or 64 - otherwise extra bits on 0 will be added in front (to the left).