In a signed binary, the first bit (the leftmost) is reserved for the sign,
1 = negative, 0 = positive. This bit does not count when calculating the absolute value.
2. Construct the unsigned binary number.
Exclude the first bit (the leftmost), that is reserved for the sign:
1101 0110 0101 0110 1010 0100 1100 1010 = 101 0110 0101 0110 1010 0100 1100 1010
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
230
1 229
0 228
1 227
0 226
1 225
1 224
0 223
0 222
1 221
0 220
1 219
0 218
1 217
1 216
0 215
1 214
0 213
1 212
0 211
0 210
1 29
0 28
0 27
1 26
1 25
0 24
0 23
1 22
0 21
1 20
0
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
101 0110 0101 0110 1010 0100 1100 1010(2) =
(1 × 230 + 0 × 229 + 1 × 228 + 0 × 227 + 1 × 226 + 1 × 225 + 0 × 224 + 0 × 223 + 1 × 222 + 0 × 221 + 1 × 220 + 0 × 219 + 1 × 218 + 1 × 217 + 0 × 216 + 1 × 215 + 0 × 214 + 1 × 213 + 0 × 212 + 0 × 211 + 1 × 210 + 0 × 29 + 0 × 28 + 1 × 27 + 1 × 26 + 0 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 1 × 21 + 0 × 20)(10) =
(1 073 741 824 + 0 + 268 435 456 + 0 + 67 108 864 + 33 554 432 + 0 + 0 + 4 194 304 + 0 + 1 048 576 + 0 + 262 144 + 131 072 + 0 + 32 768 + 0 + 8 192 + 0 + 0 + 1 024 + 0 + 0 + 128 + 64 + 0 + 0 + 8 + 0 + 2 + 0)(10) =
(1 073 741 824 + 268 435 456 + 67 108 864 + 33 554 432 + 4 194 304 + 1 048 576 + 262 144 + 131 072 + 32 768 + 8 192 + 1 024 + 128 + 64 + 8 + 2)(10) =
1 448 518 858(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1101 0110 0101 0110 1010 0100 1100 1010(2) = -1 448 518 858(10)
The number 1101 0110 0101 0110 1010 0100 1100 1010(2) converted from a signed binary (base two) and written as an integer in decimal system (base ten):
1101 0110 0101 0110 1010 0100 1100 1010(2) = -1 448 518 858(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.