How to use
- Type the number. Prefixes 0x, 0o and 0b and separators like _ or spaces are accepted.
- Choose the base it is written in.
- Read the value in every other base; copy any of them.
- Set a custom base (2–36) to see an unusual one such as base 32.
Options explained
- Input base
- Digits above 9 use letters — a is 10, f is 15, z is 35. Letters are case-insensitive.
- Large numbers
- Calculations use arbitrary-precision integers, so 64-bit and larger values are exact instead of rounding like a normal calculator.
- Two’s complement
- For negative numbers, shows the bit pattern a computer stores in the smallest fitting 8, 16, 32, 64 or 128-bit signed integer.
- Group digits
- Splits binary and hex into groups of four and decimal into groups of three for readability. Copy removes the spaces.
Quick reference
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 7 | 111 | 7 | 7 |
| 10 | 1010 | 12 | A |
| 15 | 1111 | 17 | F |
| 16 | 10000 | 20 | 10 |
| 255 | 1111 1111 | 377 | FF |
| 1024 | 100 0000 0000 | 2000 | 400 |
| 65535 | 1111 1111 1111 1111 | 177777 | FFFF |
Frequently asked questions
How do I convert binary to decimal by hand?
Multiply each bit by 2 raised to its position, counting from 0 on the right, then add. 1011 is 1×8 + 0×4 + 1×2 + 1×1 = 11.
Why is one hex digit equal to four bits?
Sixteen values (0–f) need exactly four bits (2⁴ = 16), so each hex digit maps to one nibble. That is why hex is used to write bytes compactly — two digits per byte.
Does it support fractions?
No, integers only. Fractions such as 0.1 often have no exact finite representation in binary.
What is the largest number it can convert?
There is no practical limit; numbers with thousands of digits convert instantly.
Privacy
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