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.

BaseThis 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

DecimalBinaryOctalHex
1111
21022
410044
81000108
10101012A
15111117F
16100002010
321000004020
64100000010040
100110010014464
1281000000020080
25511111111377FF
256100000000400100
1024100000000002000400

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.

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