base 12 is a positional numeral system with twelve as its base. It uses 12 different digits for representing numbers. The digits for base 12 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, and b.

conversion table

base 12	duodecimal (base 12)	base 12	duodecimal (base 12)
1	≈ 1	b	≈ b
2	≈ 2	10	≈ 10
3	≈ 3	11	≈ 11
4	≈ 4	12	≈ 12
5	≈ 5	13	≈ 13
6	≈ 6	14	≈ 14
7	≈ 7	15	≈ 15
8	≈ 8	16	≈ 16
9	≈ 9	17	≈ 17
a	≈ a	18	≈ 18