Binary Calculator
Convert a binary integer to decimal, write a decimal integer in binary, or add, subtract, multiply and divide two binary numbers.
How it works
Binary is base 2: each digit is a power of two. 1010₂ = 1×8 + 0×4 + 1×2 + 0×1 = 10. Arithmetic here is integer-only — 101₂ ÷ 10₂ does not divide evenly, so there is no result rather than a repeating fraction.
Only the digits 0 and 1 are accepted. Values stay inside JavaScript’s safe-integer range so the bits you see match the decimal exactly.
Formula
1010₂ = 8 + 2 = 10₁₀ 1010₂ + 110₂ = 10000₂ (10 + 6 = 16)
Worked examples
Binary to decimal
1010 → 10
Add two binary numbers
1010 + 110 → 10000 (decimal 16)
Useful notes
- This is not a bitwise logic calculator (AND/OR/XOR).
- For hexadecimal instead of binary, use the hex calculator.
FAQ
- How do I convert binary to decimal?
Add each digit times its place value: 1010 = 8 + 0 + 2 + 0 = 10.
- How do I convert decimal to binary?
Repeatedly divide by 2 and read the remainders from last to first. 10 → 1010.
- Why was my division rejected?
Only exact integer quotients are shown. 5 ÷ 2 is not a whole number, so 101 ÷ 10 has no binary integer result here.
Related tools
Hex Calculator
Convert between hexadecimal and decimal, or add, subtract, multiply and divide whole hex numbers.
Exponent Calculator
Raise a base to a power, including negative and fractional exponents, with overflow rejected.
Scientific Calculator
Evaluate expressions with powers, roots, logs, factorials and trigonometry in degrees or radians.
See all Math tools.