Jewelry & Gems
Calculators for jewelers and buyers: carat weight, gold purity and karat, ring size, diamond price, and gold and silver scrap melt value, with the conversions shown.
Carat Weight Calculator
Estimate a round brilliant diamond's carat weight from its diameter and depth, or convert between carats, grams and milligrams instantly.
Diamond Price Calculator
Calculate a diamond's total price from its carat weight and price per carat. Enter both numbers and see the total rounded to the cent.
Gold Purity Calculator
Convert gold purity between karat, percentage and fineness. Enter 18k, 14k, 24k or any value and see the exact percent and parts per thousand.
Gold Scrap Value Calculator
Find the melt value of karat gold. Enter grams, karat and a spot price per gram or troy ounce to see the pure gold content and its worth.
Ring Size Calculator
Convert a ring's inside diameter or circumference in millimetres to an estimated US ring size, with the matching diameter and circumference shown.
Silver Melt Value Calculator
Find the melt value of silver by purity. Enter grams, choose fine, sterling or coin, add a spot price and see the pure silver content and value.