Octal to Hex Converter
Convert a octal (base 8) number to hexadecimal (base 16) instantly. As an example, 377 = FF. It runs entirely in your browser.
| Base | This number |
|---|---|
| Binary (base 2) | — |
| Octal (base 8) | — |
| Decimal (base 10) | — |
| Hexadecimal (base 16) | — |
How to convert octal to hexadecimal
The simplest route from octal to hexadecimal goes through decimal: convert the octal value to decimal, then convert that to hexadecimal.
377 (octal) = 255 (decimal) = FF (hexadecimal)
Worked example: 377 in hexadecimal
Reading 377 as base 8: 3 × 82 (= 192) + 7 × 81 (= 56) + 7 × 80 (= 7) = 255 in decimal, which is FF in hexadecimal.
More octal-to-hexadecimal examples: 12 = A, 20 = 10, 100 = 40.
Binary, octal, decimal & hexadecimal reference table
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 1 | 1 | 1 | 1 |
| 2 | 10 | 2 | 2 |
| 4 | 100 | 4 | 4 |
| 8 | 1000 | 10 | 8 |
| 10 | 1010 | 12 | A |
| 15 | 1111 | 17 | F |
| 16 | 10000 | 20 | 10 |
| 32 | 100000 | 40 | 20 |
| 64 | 1000000 | 100 | 40 |
| 100 | 1100100 | 144 | 64 |
| 128 | 10000000 | 200 | 80 |
| 255 | 11111111 | 377 | FF |
| 256 | 100000000 | 400 | 100 |
| 1024 | 10000000000 | 2000 | 400 |
About octal and hexadecimal
Octal: Octal is base-8, using digits 0–7. Each octal digit maps to exactly three bits, which is why it appears in Unix file-permission modes such as 755.
Hexadecimal: Hexadecimal is base-16, using 0–9 then A–F. Each hex digit is exactly four bits, so it is a compact way to write bytes — used for colours (#FF8800), memory addresses and MAC addresses.
Frequently asked questions
- What is 377 octal in hexadecimal?
- 377 in octal (base 8) equals FF in hexadecimal (base 16), which is 255 in decimal.
- How do I convert octal to hexadecimal by hand?
- Convert octal to decimal first (377 = 255), then convert that decimal value to hexadecimal (255 = FF). The tool above does both steps for you.
- Is this exact for very large numbers?
- Yes. The converter uses big-integer (BigInt) arithmetic in your browser, so even very long octal values convert to hexadecimal with no rounding or precision loss.
- Which characters are valid in octal?
- Base-8 octal uses the digits 0–7. Spaces, underscores and an optional 0x/0b/0o prefix are ignored; any other character is flagged as invalid.