Octal to Decimal Converter
Convert any octal number to decimal instantly — with the full step-by-step working shown. Free, fast, no sign-up.
Only octal digits allowed (0-7) — spaces, commas and dashes are ignored.
Decimal result
Also equals
- Binary
- Decimal
- Octal
- Hex
Step-by-step calculation
| Digit | Position | Value (8n) | Contribution |
|---|---|---|---|
| Total | |||
How to convert octal to decimal
- Write down the octal number and number each digit's position from right to left, starting at 0.
- Multiply each digit (0-7) by 8 raised to the power of its position.
- Add all the results together — that's your decimal number.
Example: 175₈ = (1 × 8²) + (7 × 8¹) + (5 × 8⁰) = 64 + 56 + 5 = 125.
Frequently asked questions
How do I convert octal to decimal?
Multiply each octal digit by 8 raised to its position power (from 0 at the right) and sum the results. Or just use the converter above — it shows every step.
What is 17 in decimal?
17₈ = 15 in decimal.
Can this converter handle large octal numbers?
Yes — it supports octal numbers of any length with full precision.
Need the reverse? Try our decimal to octal converter.