Decimal value of 1011001 binary number Result 1011001 = 89 Explained 1 * 26 = 64 0 * 25 = 0 1 * 24 = 16 1 * 23 = 8 0 * 22 = 0 0 * 21 = 0 1 * 20 = 1 In result: 64 + 16 + 8 + 1 = 89