Gold & Silver Value Calculator
Weigh your piece, pick the purity (karat or fineness), and set a spot price per troy ounce. The calculator converts weight to troy ounces, applies purity, and shows melt value. Reference spot prices below include an as-of time — edit them anytime; we never invent a live quote when the feed is unavailable.
Embedded reference: gold ≈ $4103.80/oz t, silver ≈ $52.57/oz t (as of 2026-11-05 18:38 UTC / 2026-11-06 02:38 Asia/Shanghai), source gold-api.com. Click “Refresh reference price” to try a live update; if it fails, edit the spot field yourself.
How the math works
pure_troy_oz = troy_oz × purity
melt_USD = pure_troy_oz × spot_USD_per_troy_oz
purity: karat/24, or fineness (0–1)
Bullion markets quote gold and silver in US dollars per troy ounce. A troy ounce is 31.1034768 grams — heavier than an avoirdupois ounce (28.349523125 g). Jewelry is rarely pure: 18k = 18/24 = 0.750, sterling silver is usually 0.925. Melt value is the theoretical metal content at spot; it is not an offer to buy.
Worked example
An 18k gold ring that weighs 10 g, with spot at $4,103.80 / oz t:
- Troy ounces = 10 ÷ 31.1034768 ≈ 0.3215 oz t
- Pure gold = 0.3215 × 0.750 ≈ 0.2411 oz t
- Melt ≈ 0.2411 × 4103.80 ≈ $989.55
A 25 g sterling (.925) silver bracelet at $52.57 / oz t → 25/31.1034768 × 0.925 × 52.57 ≈ $39.09.
FAQ
- Why can I edit the spot price?
- Spot moves every second and free public feeds can fail. We seed a dated reference quote and let you type the number from Kitco, your dealer, or a bank board. The as-of line tells you when the seed was captured.
- Do stones and findings count?
- No. Weigh only the metal, or subtract gem weight if you know it. Prongs, clasps and solder of a different alloy also change true purity.
- Karat vs fineness?
- Karat divides 24 parts. Fineness is a decimal or stamped number like 750 (meaning 750/1000). Enter 0.750 or 75 — values above 1 are treated as percents.
- Is this investment advice?
- No. It is arithmetic for metal content. Scrap buy prices, premiums on coins, and taxes are separate.
Reference quotes are informational snapshots, not a live brokerage feed. Always confirm current spot and dealer payout before selling.