base 30 is a positional numeral system with thirty as its base. It uses 30 different digits for representing numbers. The digits for base 30 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, and t.

conversion table

base 30	base 18	base 30	base 18
1	≈ 1	b	≈ b
2	≈ 2	c	≈ c
3	≈ 3	d	≈ d
4	≈ 4	e	≈ e
5	≈ 5	f	≈ f
6	≈ 6	g	≈ g
7	≈ 7	h	≈ h
8	≈ 8	i	≈ 10
9	≈ 9	j	≈ 11
a	≈ a	k	≈ 12