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:
0001 0000 0000 1111 1011 0000 0100 1100 0000 0000 0000 0000 0000 0000 0000 0101 = 001 0000 0000 1111 1011 0000 0100 1100 0000 0000 0000 0000 0000 0000 0000 0101
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
262
0 261
0 260
1 259
0 258
0 257
0 256
0 255
0 254
0 253
0 252
0 251
1 250
1 249
1 248
1 247
1 246
0 245
1 244
1 243
0 242
0 241
0 240
0 239
0 238
1 237
0 236
0 235
1 234
1 233
0 232
0 231
0 230
0 229
0 228
0 227
0 226
0 225
0 224
0 223
0 222
0 221
0 220
0 219
0 218
0 217
0 216
0 215
0 214
0 213
0 212
0 211
0 210
0 29
0 28
0 27
0 26
0 25
0 24
0 23
0 22
1 21
0 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
001 0000 0000 1111 1011 0000 0100 1100 0000 0000 0000 0000 0000 0000 0000 0101(2) =
(0 × 262 + 0 × 261 + 1 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 0 × 256 + 0 × 255 + 0 × 254 + 0 × 253 + 0 × 252 + 1 × 251 + 1 × 250 + 1 × 249 + 1 × 248 + 1 × 247 + 0 × 246 + 1 × 245 + 1 × 244 + 0 × 243 + 0 × 242 + 0 × 241 + 0 × 240 + 0 × 239 + 1 × 238 + 0 × 237 + 0 × 236 + 1 × 235 + 1 × 234 + 0 × 233 + 0 × 232 + 0 × 231 + 0 × 230 + 0 × 229 + 0 × 228 + 0 × 227 + 0 × 226 + 0 × 225 + 0 × 224 + 0 × 223 + 0 × 222 + 0 × 221 + 0 × 220 + 0 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 0 × 215 + 0 × 214 + 0 × 213 + 0 × 212 + 0 × 211 + 0 × 210 + 0 × 29 + 0 × 28 + 0 × 27 + 0 × 26 + 0 × 25 + 0 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 1 × 20)(10) =
(0 + 0 + 1 152 921 504 606 846 976 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 562 949 953 421 312 + 281 474 976 710 656 + 140 737 488 355 328 + 0 + 35 184 372 088 832 + 17 592 186 044 416 + 0 + 0 + 0 + 0 + 0 + 274 877 906 944 + 0 + 0 + 34 359 738 368 + 17 179 869 184 + 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 + 0 + 4 + 0 + 1)(10) =
(1 152 921 504 606 846 976 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 562 949 953 421 312 + 281 474 976 710 656 + 140 737 488 355 328 + 35 184 372 088 832 + 17 592 186 044 416 + 274 877 906 944 + 34 359 738 368 + 17 179 869 184 + 4 + 1)(10) =
1 157 337 469 721 509 893(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0001 0000 0000 1111 1011 0000 0100 1100 0000 0000 0000 0000 0000 0000 0000 0101(2) = 1 157 337 469 721 509 893(10)
The number 0001 0000 0000 1111 1011 0000 0100 1100 0000 0000 0000 0000 0000 0000 0000 0101(2) converted from a signed binary (base two) and written as an integer in decimal system (base ten):
0001 0000 0000 1111 1011 0000 0100 1100 0000 0000 0000 0000 0000 0000 0000 0101(2) = 1 157 337 469 721 509 893(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.