Binary to Decimal Converter
Type a binary number and see its decimal value — plus the full step-by-step working.
How the Binary to Decimal Converter Works
Binary is a base-2 system: every digit is a bit, 0 or 1, and each position is worth a power of 2. Starting from the right, the positions are worth 1, 2, 4, 8, 16, and so on. To convert, multiply each bit by its position value and add the results.
Example: 1011 in binary. From the right: 1 × 1 = 1, 1 × 2 = 2, 0 × 4 = 0, 1 × 8 = 8. Add them: 1 + 2 + 0 + 8 = 11. So 1011 in binary equals 11 in decimal. The converter below shows exactly this working for any binary number you enter.
Computers use binary because their circuits have two states — on and off — which map naturally to 1 and 0. That is why programmers, students, and electronics hobbyists convert between binary and decimal so often.
Frequently Asked Questions
How do I convert binary to decimal by hand?
What is 1011 in decimal?
Can I convert binary fractions?
Why do computers use binary?
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