Octal to Binary
Convert octal numbers to binary instantly. For example, 65 in octal is 110101 in binary.
Octal to Binary — quick reference
| Octal | Binary |
|---|
How to use the Octal to Binary
- Type or paste your octal value on the left.
- Read the binary result on the right — separate multiple values with spaces.
- Copy the result, or check the reference table below.
About the Octal to Binary
This tool converts octal numbers to binary. Octal is base 8, written with the digits 0 through 7; binary is base 2, written with 0 and 1. Type a value on the left and the binary result appears instantly, and you can convert several values at once by separating them with spaces.
Worked example. Go through decimal as a bridge: 65 in octal is 53 in decimal, and 53 in decimal is 110101 in binary. This tool does both steps at once.
Every octal digit unpacks into precisely three bits, so this direction is handy when you want to see what a permission number like 640 really sets, bit by bit, rather than as a compact code. Nothing is lost along the way — expanding base 8 back into base 2 restates the same whole number, so there is no rounding and no approximation. The reference table beneath the tool holds more octal-to-binary pairs you can verify at a glance, and since the maths runs inside your browser, the values you type stay on your computer. For the reverse direction use the binary to Octal converter, or the all-in-one number base converter for arbitrary bases.
Frequently asked questions
What is 65 in octal converted to binary?
65 in octal equals 110101 in binary. You can confirm it with the worked example above, or by typing 65 into the converter.
Is this octal to binary conversion exact?
Yes. Converting a whole number between bases changes only how it is written, not its value, so there is no rounding. 65 and 110101 are the same quantity expressed in base 8 and base 2.
Can I convert more than one octal value at once?
Yes. Separate each octal value with a space and every one is converted to binary on its own, in order.
Is my data uploaded anywhere?
No. The conversion runs entirely in your browser with JavaScript; nothing you type is sent to a server.