convertimate Gold purity

Millesimal fineness to percent gold

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

1.8%

Nothing on our list is smaller: 9 karat gold is 21× purer. A 10 g piece at that purity holds about 0.18 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 fineness to %

To convert millesimal fineness to percent gold, multiply by 0.1.

Example: 18 fineness × 0.1 = 1.8 %.

In the other direction, 1 % = 10 fineness.

Every unit

Your purity in every unit

Tables

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 %
% 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

Quick answers

Quick answers

How many % is 1 fineness?
1 fineness is 0.1 %.
How many % is 10 fineness?
10 fineness is 1 %.
How many % is 18 fineness?
18 fineness is 1.8 %.

The units

About these units

Millesimal fineness (fineness)

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

Percent gold (%)

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

Learn more about purity units

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