Octal to decimal
Type a value in oct to get it in dec instantly.
255dec
That's about the same as a byte. That needs 8 bits to store.
Convert the other way: dec to oct
What it means
How big is that?
Whole numbers only. Anything after the decimal point is rounded away.
The math
How to convert oct to dec
Base b: each digit is worth b times the one to its right. Gray code = n XOR (n ÷ 2); BCD writes each decimal digit as four bits.
Example: 377 oct = 255 dec.
Every unit
Your number in every base
Tables
oct to dec conversion table
| oct | dec |
|---|---|
| 1 oct | 1 dec |
| 2 oct | 2 dec |
| 4 oct | 4 dec |
| 10 oct | 8 dec |
| 12 oct | 10 dec |
| 17 oct | 15 dec |
| 20 oct | 16 dec |
| 37 oct | 31 dec |
| 40 oct | 32 dec |
| 100 oct | 64 dec |
| 144 oct | 100 dec |
| 200 oct | 128 dec |
| 377 oct | 255 dec |
| 400 oct | 256 dec |
| 1000 oct | 512 dec |
| 1750 oct | 1,000 dec |
| 2000 oct | 1,024 dec |
dec to oct conversion table
| dec | oct |
|---|---|
| 1 dec | 1 oct |
| 2 dec | 2 oct |
| 4 dec | 4 oct |
| 8 dec | 10 oct |
| 10 dec | 12 oct |
| 15 dec | 17 oct |
| 16 dec | 20 oct |
| 31 dec | 37 oct |
| 32 dec | 40 oct |
| 64 dec | 100 oct |
| 100 dec | 144 oct |
| 128 dec | 200 oct |
| 255 dec | 377 oct |
| 256 dec | 400 oct |
| 512 dec | 1000 oct |
| 1,000 dec | 1750 oct |
| 1,024 dec | 2000 oct |
Quick answers
Quick answers
- How many dec is 1 oct?
- 1 oct is 1 dec.
- How many dec is 12 oct?
- 12 oct is 10 dec.
- How many dec is 377 oct?
- 377 oct is 255 dec.
The units
About these units
Octal (oct)
Base eight, digits 0 to 7. It survives in Unix file permissions such as 755.
Decimal (dec)
Base ten, the everyday counting system, using digits 0 to 9.
Keep going