Octal number is a number expressed in the base 8 numeral system. Octal number's digits have 8 symbols: 0,1,2,3,4,5,6,7. Each digit of an octal number counts a power of 16.
Octal number example:
6278 = 6×82+2×81+7×80 = 158010
Decimal number is a number expressed in the base 10 numeral system. Decimal number's digits have 10 symbols: 0,1,2,3,4,5,6,7,8,9. Each digit of a decimal number counts a power of 10.
Decimal number example:
65310 = 6×102+5×101+3×100
A regular decimal number is the sum of the digits multiplied with 10n.
137 in base 10 is equal to each digit multiplied with its corresponding 10n:
13710 = 1×102+3×101+7×100 = 100+30+7
Octal numbers are read the same way, but each digit counts 8n instead of 10n.
Multiply each digit of the hex number with its corresponding 8n.
37 in base 8 is equal to each digit multiplied with its corresponding 8n:
378 = 3×81+7×80 = 24+7 = 31
7014 in base 8 is equal to each digit multiplied with its corresponding power of 8:
70148 = 7×83+0×82+1×81+4×80= 3584+0+8+4 = 3596
| 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 |
| 30 | 24 |
| 40 | 32 |
| 50 | 40 |
| 60 | 48 |
| 70 | 56 |
| 100 | 64 |
