How to Convert Octal to Hexadecimal
Convert an octal integer to hexadecimal by using binary as the bridge. The tool exposes every 3-bit octal mapping, 4-bit hexadecimal group, and decimal verification.
Written and checked by TheToolNet Editorial Team · Last reviewed: September 19, 2026 · How we check conversion tools
Replace each octal digit with three bits, join the bits, regroup them into fours from the right, and map each group to hex.
Octal to hexadecimal converter
Enter digits 0–7. Spaces, underscores, and an optional 0o prefix are accepted.
Octal to hexadecimal conversion method
- Write each octal digit as three binary bits: 0 = 000 through 7 = 111.
- Join the bit groups without changing their order.
- Starting at the right, split the binary string into groups of four. Pad only the leftmost group with zeros if needed.
- Replace each four-bit group with one hexadecimal digit.
Worked example: convert 1750 octal to hex
Map the octal digits: 1 → 001, 7 → 111, 5 → 101, and 0 → 000. Joined, that is 001111101000. Regroup it as 0011 1110 1000, which maps to 3 E 8. Therefore 1750₈ = 3E8₁₆. Both equal decimal 1000.
Can you convert through decimal instead?
Yes. Expand the octal number using powers of 8, then repeatedly divide the decimal result by 16. That method is valid, but the binary bridge usually needs less arithmetic because 8 and 16 are both powers of 2.
For a direct bit-grouping example, see the binary to hexadecimal converter.
Common conversion mistakes
- Using 8 or 9 in an octal input. Valid octal digits stop at 7.
- Grouping the joined binary digits from the left instead of the right.
- Removing zeros inside the number. Only leading padding zeros may be discarded.
- Reading A–F as letters rather than values 10–15.
Frequently asked questions
What is the easiest way to convert octal to hexadecimal?
Use binary as a bridge: three bits per octal digit, then four bits per hexadecimal digit.
What is 345 octal in hexadecimal?
345₈ is E5₁₆. In binary, 345₈ becomes 011 100 101, which regroups as 1110 0101.
Does this converter support octal fractions?
No. It handles unsigned whole numbers. Fractional conversion requires grouping bits on both sides of the radix point.