How to convert from octal to decimal

 

How to convert from octal to decimal

A regular decimal number is the sum of the digits multiplied with 10n.

Example #1

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.

Example #2

37 in base 8 is equal to each digit multiplied with its corresponding 8n:

378 = 3×81+7×80 = 24+7 = 31

Example #3

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

Example #4

112 = (1 × 8²) + (1 × 8¹) + (2 × 8⁰) = 74

Octal to decimal conversion table

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

 

Decimal to Octal converter ►