Gold purity converter — karat, percent, fineness
Convert between karat, purity percentage and hallmark fineness, and find the pure gold in a weight. It converts entirely in your browser (0 uploads, works offline).
How to use it
- Enter the karat and optionally a weight.
- Read the purity percentage, fineness and pure-gold content.
- Copy or Download the result.
FAQ
How do I convert karat to purity for free?
Enter the karat and this page gives the purity as a percentage (karat ÷ 24 × 100), the hallmark fineness in parts per thousand, and the pure gold in any weight you enter — on your device with no upload.
Why is 22K written as 916?
22 karat is 22 ÷ 24 = 91.6% pure, which the BIS hallmark expresses as 916 parts per thousand. Similarly 18K is 750 and 24K is close to 999.
Is anything uploaded?
No. The conversion runs entirely in your browser and nothing is transmitted or stored, which you can verify by turning off your Wi-Fi.
How much pure gold is in my jewellery?
Enter the karat and the weight; the tool multiplies the weight by the purity to show the pure-gold content in grams.
Limits
Converts standard karat purity; it does not price the gold or account for stones and alloys in a finished piece.
Related
The gold making charges calculator prices ornaments; the jewellery GST calculator adds tax.
Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.