Convert octal to decimal
Octal (base 8) to decimal (base 10). Type a value below, or use the reference table further down.
Multiply each digit by 8 raised to its position, counting from zero on the right, then add the results. 755 comes to 493 in decimal.
How to convert octal to decimal
Multiply each digit by 8 raised to its position, counting from zero on the right, then add the results. 755 comes to 493 in decimal.
Conversions here use arbitrary-precision integers, so values beyond 64 bits convert exactly rather than being rounded.
octal to decimal conversion table
Use this octal to decimal chart for quick reference.
| Octal (base 8) | Decimal (base 10) |
|---|---|
| 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 |
| 40 | 32 |
| 100 | 64 |
| 144 | 100 |
| 177 | 127 |
| 200 | 128 |
| 377 | 255 |
| 400 | 256 |
| 1000 | 512 |
| 1750 | 1000 |
| 1777 | 1023 |
| 2000 | 1024 |
| 7777 | 4095 |
| 10000 | 4096 |
| 177777 | 65535 |
| 200000 | 65536 |
Common octal to decimal values
1020307010014420037740075577710001750
What is octal?
Octal is base 8, using the digits 0 to 7. One octal digit encodes exactly three bits, which is why Unix file permissions are written as octal numbers such as 755.
What is decimal?
Decimal is base 10, the everyday number system, using the digits 0 to 9. Each place is worth ten times the one to its right.
Frequently asked questions
How do you convert octal to decimal?
Multiply each digit by 8 raised to its position, counting from zero on the right, then add the results. 755 comes to 493 in decimal.
What is 755 octal in decimal?
755 in octal is 493 in decimal. In plain decimal that value is 493.
What digits does octal use?
Octal is base 8 and uses 0-7. Octal is base 8, using the digits 0 to 7. One octal digit encodes exactly three bits, which is why Unix file permissions are written as octal numbers such as 755.