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 |
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 |
| hexadecimal (base 16) | duodecimal (base 12) |
|---|---|
| 1 | = 1 |
| 2 | = 2 |
| 3 | = 3 |
| 4 | = 4 |
| 5 | = 5 |
| 6 | = 6 |
| 7 | = 7 |
| 8 | = 8 |
| 9 | = 9 |
| a | = a |