base 19 is a positional numeral system with nineteen as its base. It uses 19 different digits for representing numbers. The digits for base 19 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, and i.

conversion table

base 19	duodecimal (base 12)	base 19	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	10	≈ 17
a	≈ a	11	≈ 18