Free Gold Karat Calculator. Instantly check the purity percentage of 14K, 20K, and 23K gold. Convert weight from 24K to 22K, or 18K to 22K accurately. Calculate the true value of your gold in seconds.
Gold Karat & Purity Calculator
Use our free gold karat calculator to convert between any karats, check the purity percentage of your gold, and calculate exactly how much pure 24K gold or alloy to add to change your gold’s karat. Whether you’re a jeweler, refiner, or selling scrap gold, this tool gives you accurate, real-time results for standard and decimal karats.
How to Use the Gold Karat Calculator
Easy Mode — For standard karats (24K, 22K, 21K, 20K, 18K, 14K, 10K). Perfect for quick conversions.
Expert Mode — For decimal karats like 22.5K, 18.5K, or 17.5K. Common in Middle Eastern, Asian, and custom jewelry markets.
Alloying Mode — To calculate how much pure 24K gold to add (upgrade) or how much non-gold alloy to add (downgrade) to reach your target karat.