The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Octal numerals can be made from binary numerals by grouping consecutive binary digits into groups of three (starting from the right). For example, the binary representation for decimal 74 is 1001010. Two zeroes can be added at the left: (00)1 001 010, corresponding the octal digits 1 1 2, yielding the octal representation 112.
| octal (base 8) | hexatrigesimal (base 36) | octal (base 8) | hexatrigesimal (base 36) |
|---|---|---|---|
| 1 | = 1 | 13 | = b |
| 2 | = 2 | 14 | = c |
| 3 | = 3 | 15 | = d |
| 4 | = 4 | 16 | = e |
| 5 | = 5 | 17 | = f |
| 6 | = 6 | 20 | = g |
| 7 | = 7 | 21 | = h |
| 10 | = 8 | 22 | = i |
| 11 | = 9 | 23 | = j |
| 12 | = a | 24 | = k |
Base36 is a binary-to-text encoding scheme that represents binary data in an ASCII string format by translating it into a radix-36 (aka Hexatrigesimal) representation. The choice of 36 is convenient in that the digits can be represented using the Arabic numerals 0–9 and the Latin letters A–Z (the ISO basic Latin alphabet).
| hexatrigesimal (base 36) | octal (base 8) | hexatrigesimal (base 36) | octal (base 8) |
|---|---|---|---|
| 1 | ≈ 1 | b | ≈ 13 |
| 2 | ≈ 2 | c | ≈ 14 |
| 3 | ≈ 3 | d | ≈ 15 |
| 4 | ≈ 4 | e | ≈ 16 |
| 5 | ≈ 5 | f | ≈ 17 |
| 6 | ≈ 6 | g | ≈ 20 |
| 7 | ≈ 7 | h | ≈ 21 |
| 8 | ≈ 10 | i | ≈ 22 |
| 9 | ≈ 11 | j | ≈ 23 |
| a | ≈ 12 | k | ≈ 24 |
| octal (base 8) | hexatrigesimal (base 36) |
|---|---|
| 1 | = 1 |
| 2 | = 2 |
| 3 | = 3 |
| 4 | = 4 |
| 5 | = 5 |
| 6 | = 6 |
| 7 | = 7 |
| 10 | = 8 |
| 11 | = 9 |
| 12 | = a |