Binary to Octal
Convert a binary number to its octal (base-8) value.
About the Binary to Octal converter
This tool converts a binary number into octal, its base-8 equivalent. Binary and octal are close relatives: every group of three binary digits maps to a single octal digit, so 11010 groups as 011 010 and becomes 32 in octal. That tidy relationship is why octal has long been a compact shorthand for binary, especially in Unix permission bits.
How to use it
- Enter a binary number using only 1s and 0s.
- The octal equivalent appears straight away.
- Copy the result for use in a script, permission mask, or notes.
A typical use is shortening a long bit pattern into the three-digit octal form used for file permissions like 755. The converter treats the input as an unsigned whole number and handles long bit strings exactly, so large values convert without rounding. It does not read a leading bit as a sign. Everything runs in your browser, so the numbers you enter are never uploaded.
Frequently asked questions
Why do three binary digits make one octal digit?
Octal is base-8 and 8 equals 2 to the third power, so each octal digit corresponds exactly to three binary digits. Binary is grouped in threes from the right to read off the octal value.
How does this relate to Unix file permissions?
Permission bits are commonly written in octal, where each digit packs three permission bits. Converting binary to octal is a quick way to see the familiar three-digit form such as 755.
Does it handle very large binary numbers?
Yes. The conversion uses exact integer arithmetic, so long bit strings convert without losing precision.
Is the binary I enter sent anywhere?
No. The conversion runs in your browser, so your input stays on your device.