convertimate Gold purity

Percent gold to millesimal fineness

Type a value in % to get it in fineness instantly.

180fineness

Nothing on our list is smaller: 9 karat gold is 2.1× purer. A 10 g piece at that purity holds about 1.8 g of pure gold.

What it means

How pure is that?

Karat measures purity, not weight. Carat with a c is a gemstone weight of 200 mg, and a different thing entirely.

The math

How to convert % to fineness

To convert percent gold to millesimal fineness, multiply by 10.

Example: 18 % × 10 = 180 fineness.

In the other direction, 1 fineness = 0.1 %.

Every unit

Your purity in every unit

Tables

% to fineness conversion table

% to fineness conversion table
%fineness
8 %80 fineness
9 %90 fineness
10 %100 fineness
12 %120 fineness
14 %140 fineness
15 %150 fineness
18 %180 fineness
20 %200 fineness
21 %210 fineness
22 %220 fineness
23 %230 fineness
24 %240 fineness
fineness to % conversion table
fineness to % conversion table
fineness%
8 fineness0.8 %
9 fineness0.9 %
10 fineness1 %
12 fineness1.2 %
14 fineness1.4 %
15 fineness1.5 %
18 fineness1.8 %
20 fineness2 %
21 fineness2.1 %
22 fineness2.2 %
23 fineness2.3 %
24 fineness2.4 %

Quick answers

Quick answers

How many fineness is 1 %?
1 % is 10 fineness.
How many fineness is 10 %?
10 % is 100 fineness.
How many fineness is 18 %?
18 % is 180 fineness.

The units

About these units

Percent gold (%)

The share of gold by weight: 18 kt is 75%.

Millesimal fineness (fineness)

Parts per thousand, the number stamped inside jewellery: 750 is 18 kt.

Learn more about purity units

Keep going

Related conversions