Octal to Decimal Converter
Convert octal to decimal instantly — type on the left and the result appears on the right. Everything runs in your browser, nothing is uploaded.
How to convert octal to decimal
Octal is base 8, so each place is worth eight times the one to its right. Multiply each digit by its place value and add the results.
Formula: value = d₀ + d₁×8 + d₂×8² + … (each digit times a power of 8).
- Give each digit its place valueReading from the right, the places are powers of 8: 1, 8, 64, 512 and so on.
- Note each digit's valueEach digit is a number from 0 to 7.
- Multiply and addMultiply each digit by its place value and add the totals to get the decimal number.
Examples 32 = 26377 = 255
Octal to Decimal Table
Common octal values with their decimal equivalents.
| Octal | Decimal |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
| 7 | 7 |
| 10 | 8 |
| 11 | 9 |
| 12 | 10 |
| 13 | 11 |
| 14 | 12 |
| 15 | 13 |
| 16 | 14 |
| 17 | 15 |
| 20 | 16 |
| 24 | 20 |
| 40 | 32 |
| 62 | 50 |
| 100 | 64 |
| 144 | 100 |
| 200 | 128 |
| 377 | 255 |
| 400 | 256 |
| 1000 | 512 |
| 1750 | 1000 |
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Frequently asked questions
How do you convert octal to decimal?
Give each digit a place value that is a power of 8 — 1, 8, 64, 512 — multiply each digit by its place value and add. 144 gives 100.
What is octal 10 in decimal?
Octal 10 is 8 in decimal.
What is 777 in decimal?
Octal 777 is 511 in decimal (7×64 + 7×8 + 7).