Decimal to Octal Converter
Convert decimal to octal — repeated division by eight, remainders read upwards.
Divide by eight and keep the remainder; repeat on the quotient until it reaches zero; read the remainders bottom to top.
How the decimal to octal converter works
Divide by eight and keep the remainder; repeat on the quotient until it reaches zero; read the remainders bottom to top. 255 gives remainders 7, 7, 3 — so 377.
The same method converts to any base; only the divisor changes.
Formula: value = Σ digitₖ × bᵏ
Worked examples
| Inputs | Converted | Note |
|---|---|---|
| 255 | 377 | 377 |
| 493 | 755 | 755 |
| 8 | 10 | 10 |
FAQFrequently asked questions
How do I convert decimal to octal?
Divide by 8 repeatedly and read the remainders from the bottom up.
What is 255 in octal?
377.
Why does 8 become 10?
Because octal runs out of digits at 7, so eight is the first two-digit value — exactly as ten is in decimal.
Where is octal used?
Unix file permissions, and some older computing contexts.
What is the largest single octal digit?
7.
Where these figures come from
- NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
- Wolfram MathWorld — definitions and formulas for every topic on this page
- NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
- Common Core State Standards — Mathematics — the terms and methods taught in US schools
Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.