The duodecimal system (also known as base 12 or dozenal) is a positional notation numeral system using twelve as its base.
| duodecimal (base 12) | hexadecimal (base 16) | duodecimal (base 12) | hexadecimal (base 16) |
|---|---|---|---|
| 1 | = 1 | b | = b |
| 2 | = 2 | 10 | = c |
| 3 | = 3 | 11 | = d |
| 4 | = 4 | 12 | = e |
| 5 | = 5 | 13 | = f |
| 6 | = 6 | 14 | = g |
| 7 | = 7 | 15 | = h |
| 8 | = 8 | 16 | = i |
| 9 | = 9 | 17 | = j |
| a | = a | 18 | = 10 |
The vigesimal or base 20 numeral system is based on twenty (in the same way in which the decimal numeral system is based on ten).
| hexadecimal (base 16) | duodecimal (base 12) | hexadecimal (base 16) | duodecimal (base 12) |
|---|---|---|---|
| 1 | ≈ 1 | b | ≈ b |
| 2 | ≈ 2 | c | ≈ 10 |
| 3 | ≈ 3 | d | ≈ 11 |
| 4 | ≈ 4 | e | ≈ 12 |
| 5 | ≈ 5 | f | ≈ 13 |
| 6 | ≈ 6 | g | ≈ 14 |
| 7 | ≈ 7 | h | ≈ 15 |
| 8 | ≈ 8 | i | ≈ 16 |
| 9 | ≈ 9 | j | ≈ 17 |
| a | ≈ a | 10 | ≈ 18 |
| duodecimal (base 12) | hexadecimal (base 16) |
|---|---|
| 1 | = 1 |
| 2 | = 2 |
| 3 | = 3 |
| 4 | = 4 |
| 5 | = 5 |
| 6 | = 6 |
| 7 | = 7 |
| 8 | = 8 |
| 9 | = 9 |
| a | = a |