Article - Precious Metal -Gold Purity.

Karat purity is measured as 24 times the purity by mass:

Gold Purity
24kt  gold =  100.00%
22kt  gold =  91.60%
18kt  gold =  75.00%
14kt  gold =  58.5%
10kt  gold =  41.7%
9kt    gold =  7.5%