Binary to Octal
Binary to octal converts one binary number, including a fractional part, with three-bit grouping steps.
All input bits are converted. No fractional-place cutoff, rounding or truncation is applied.
Calculation steps
Frequently asked questions
How do I convert binary to octal?
Enter one binary number and select Convert to octal. Starting at the point, group integer bits toward the left and fractional bits toward the right in groups of three. Each group becomes one octal digit. Open Calculation steps to see the groups for your input.
Does this binary to octal converter accept fractions?
Yes. Use a point between the integer and fractional bits. For example, 111101.1011 produces 75.54. If a fractional group has fewer than three bits, zeros are added on its right. Incomplete integer groups receive zeros on their left. These padding zeros do not change the value.
How many fractional places are kept?
Every fractional input bit is processed. Finite binary fractions have finite octal results, so this page needs no rounding or fractional-place setting. Leading integer zeros and trailing fractional zeros are removed from the displayed result; an all-zero value is displayed as 0.
Can I use spaces, a prefix or a minus sign?
Yes. Whitespace groups one value and is removed, so 11 1101.10 11 means 111101.1011, not a batch. An optional leading plus or minus sign and an optional 0b prefix are accepted. A leading or trailing point is accepted when at least one binary digit is present. Negative values use a minus sign, not a fixed-width two's-complement interpretation.
Which inputs are rejected and what is the limit?
Use only binary digits 0 and 1, with the optional syntax described above. Commas, exponent notation, hexadecimal or octal prefixes, multiple points and other characters are rejected. Invalid input clears the old result. This tool processes one number per run, with at most 1,000 binary digits and 10,000 total input characters including whitespace.
Does this translate binary into text?
No. It converts the numeric value of the whole input into octal, rather than interpreting bytes as letters. For text bytes use Binary Translator. For decimal integers use Binary to Decimal. For decimal input and octal output use Decimal to Octal; for octal input and decimal output use Octal to Decimal.
Do I need to log in or upload anything?
No. Conversion and copying run locally in your browser. Input is not transmitted by the tool. There is no batch mode or saved conversion history.
For octal input expanded directly into binary bits, use Octal to Binary.