Convert octal to decimal instantly. Enter a valid integer — results update live with exact BigInt precision.
Selected Octal values converted to Decimal using exact positional base math.
| Octal | Decimal |
|---|---|
| 0 | 0 |
| 7 | 7 |
| 10 | 8 |
| 777 | 511 |
Positional base conversion in both directions, plus a worked example.
decimal = convert(octal digits → integer → decimal digits)
octal = convert(decimal digits → integer → octal digits)
Positional bases use place values, not a single multiplier. Each octal digit is parsed against base 8, converted to an exact integer, then written in decimal.
To go the other way, parse decimal digits, convert to the same integer, and format in octal. The live converter handles both directions.
Worked example on this page:
777 octal = 511 decimal
Short background on the units used in this conversion.
Octal (Base-8) uses positional notation in base 8. Each digit position represents a power of the base — this is notation, not a currency or measurement unit.
Octal was widely used in early Unix file permissions and some legacy systems.
Decimal (Base-10) expresses the same integer value using a different radix. The numeric value is identical; only the digit representation changes.
Decimal output is easiest to read for everyday quantities and verification.
Jump to any number base conversion starting from base_8 — including the reverse direction and every other unit in our dataset.