Octal converter
Enter an octal number (base 8, digits 0–7) to see its decimal, binary, and hexadecimal equivalents. Useful for Unix file permissions and legacy systems.
BIN—
OCT—
DEC—
HEX—
INPUT BASE
All bases shown simultaneously.
Runs entirely in your browser
How it works
Conversion uses JavaScript's built-in parseInt(value, fromBase).toString(toBase). All four bases are computed simultaneously from the same input value, so you can see binary, octal, decimal, and hex at a glance.
Processing runs in your browser
All conversion runs in your browser tab. Our servers are not involved at any point.
Related operations
For converting between data sizes like KB and MB, try the byte converter. To compute MD5 or SHA hashes from values, use the hash generator. For working with file permission bits, see the chmod calculator.
Frequently asked questions
- What is octal used for?
- Octal is commonly used for Unix/Linux file permissions (e.g. chmod 755), legacy systems, and some network protocols. Each octal digit represents exactly 3 binary bits.
- Does it accept the 0o prefix?
- Yes. Both '755' and '0o755' are accepted as octal inputs.
Related tools
Byte converter
Convert between bytes, KB, MB, GB and TB in both decimal (SI) and binary (IEC) units.
Hash generator
Generate SHA-256, SHA-512, SHA-1, and MD5 hashes. Verify file checksums locally.
Unit converter
Convert length, weight, temperature, speed and volume between metric and imperial. Instant results.
Chmod calculator
Click permission bits to get the numeric (755) and symbolic (rwxr-xr-x) notation instantly.
CIDR / subnet calculator
Calculate network address, broadcast, host range and usable hosts from any CIDR block.