The duodecimal system (also known as base 12 or dozenal) is a positional notation numeral system using twelve as its base.
| duodecimal (base 12) | base 9 | duodecimal (base 12) | base 9 |
|---|---|---|---|
| 1 | = 1 | b | = 12 |
| 2 | = 2 | 10 | = 13 |
| 3 | = 3 | 11 | = 14 |
| 4 | = 4 | 12 | = 15 |
| 5 | = 5 | 13 | = 16 |
| 6 | = 6 | 14 | = 17 |
| 7 | = 7 | 15 | = 18 |
| 8 | = 8 | 16 | = 20 |
| 9 | = 10 | 17 | = 21 |
| a | = 11 | 18 | = 22 |
| base 9 | duodecimal (base 12) | base 9 | duodecimal (base 12) |
|---|---|---|---|
| 1 | ≈ 1 | 12 | ≈ b |
| 2 | ≈ 2 | 13 | ≈ 10 |
| 3 | ≈ 3 | 14 | ≈ 11 |
| 4 | ≈ 4 | 15 | ≈ 12 |
| 5 | ≈ 5 | 16 | ≈ 13 |
| 6 | ≈ 6 | 17 | ≈ 14 |
| 7 | ≈ 7 | 18 | ≈ 15 |
| 8 | ≈ 8 | 20 | ≈ 16 |
| 10 | ≈ 9 | 21 | ≈ 17 |
| 11 | ≈ a | 22 | ≈ 18 |
| duodecimal (base 12) | base 9 |
|---|---|
| 1 | = 1 |
| 2 | = 2 |
| 3 | = 3 |
| 4 | = 4 |
| 5 | = 5 |
| 6 | = 6 |
| 7 | = 7 |
| 8 | = 8 |
| 9 | = 10 |
| a | = 11 |