Binary Converter
Type an integer in decimal, binary or hexadecimal and read the other two bases instantly — exact even for very large numbers.
Reviewed by the OmniCalc teamMethod verified 2026-07-01
Digits 0–9; a leading − is allowed
11111111
Binary (base 2) 11111111- Decimal (base 10)
- 255
- Binary (base 2)
- 11111111
- Hexadecimal (base 16)
- FF
- Binary (base 2)
- 11111111
Show steps
- Start from 255 in decimal (base 10).
- Convert to binary (base 2): 11111111.
- Convert to hexadecimal (base 16): FF.
How to use the binary converter
- 1Pick the base your number is written in — decimal, binary or hex.
- 2Type the integer (a leading − is fine). Switching the base re-expresses the value in the new digits.
- 3Read all three representations at once, with the place-value expansion under Show steps.
Four bits, one hex digit
Every hex digit corresponds to exactly four binary digits (a nibble): F = 1111, A = 1010. To convert binary by hand, group the bits in fours from the right and translate each group. That’s why programmers love hex — it’s compact binary.
Frequently asked questions
How does binary work?
Binary is base 2: each digit is a power of two, so 1011 means 1×8 + 0×4 + 1×2 + 1×1 = 11. Computers use it because a digit that is only ever 0 or 1 maps directly onto a switch that is off or on.
How do I convert binary to hexadecimal by hand?
Group the bits in fours starting from the right, then replace each group with one hex digit: 11111111 → 1111 1111 → FF. Pad the leftmost group with zeros if needed. Four bits always equal exactly one hex digit, which is why the two bases translate so cleanly.
Does it handle negative or very large numbers?
Negative integers work — the sign stays in front of the digits, so -10 in decimal is -1010 in binary. Size is unlimited: the converter uses big-integer arithmetic, so every digit stays exact even far beyond 2^53, where ordinary floating-point numbers start rounding.
Can I convert fractions or numbers with a decimal point?
No — this tool converts whole numbers only. Fractional values have their own binary expansions (decimal 0.1 is actually infinite in binary), which is a separate topic; here a decimal point simply makes the input invalid.