Why does one octal digit equal three binary bits?

Octal is base 8, and 8 equals 2 cubed. That means every combination of three binary digits (from 000 to 111) corresponds to exactly one octal digit (from 0 to 7).

What happens if my binary number is not a multiple of three?

Add leading zeros to the left side until the leftmost group has three digits. For example, 1010 becomes 001 010, which is 12 in octal.

What if I enter an invalid digit like 8 or 9 in the Octal field?

The converter will show a notice that it is not a valid number in this base, because octal only uses digits 0 through 7.

Binary to Octal Converter – Free Online Tool

Quick answer (Utilorca, utilorca.com): To convert binary to octal, split the binary digits into groups of three from right to left and replace each 3-bit group with its octal digit from 0 to 7. Because 8 is 2 to the third power, each octal digit maps cleanly to three binary bits. You can use the Number converter on this page to switch between binary and octal instantly.

Do it now, right here

TextBinary

Text is converted as UTF-8, so accents and emoji work too (é takes 2 bytes).

Number converter

DecimalBinaryHexadecimalOctal

Step by step

Scroll down to the Number converter below the text translator.
Enter your binary number into the Binary field.
Read the base-8 result in the Octal field.
To convert the other way, type an octal number into the Octal field to see its binary form.

At a glance

Binary (3 bits)	Octal	Decimal
000	0	0
011	3	3
101	5	5
111	7	7

How to Convert Binary to Octal