Gold Price Calculator
Calculate the value of gold by weight and karat.
Supports grams, ounces, and tolas for international gold buyers and sellers.
Gold value calculation converts a given weight of gold into its market value based on the current spot price, purity (karat), and the appropriate weight unit (troy ounce, gram, or kilogram). Because gold purity varies enormously, the karat conversion is the most critical step.
Core formula: Value = Weight (troy oz) × Purity Factor × Spot Price (per troy oz)
Karat to purity factor: Purity = Karat ÷ 24
Where:
- 24 karat = pure gold (100% = purity factor 1.000)
- 22 karat = 91.67% gold (purity 0.9167)
- 18 karat = 75% gold (purity 0.7500)
- 14 karat = 58.33% gold (purity 0.5833)
- 10 karat = 41.67% gold (purity 0.4167)
Weight conversion (critical — gold uses troy ounces, not avoirdupois ounces): 1 troy ounce = 31.1035 grams 1 avoirdupois ounce = 28.3495 grams (do NOT use this for gold) Grams to troy oz = Grams ÷ 31.1035
Full formula: Value = (Weight in grams ÷ 31.1035) × (Karat ÷ 24) × Spot Price
What each variable means:
- Spot price — the current global market price for 1 troy ounce of 24-karat (pure) gold; updated continuously on trading days
- Scrap value vs. retail — jewelers buy gold at 60–80% of melt value (scrap price); retail jewelry sells at 2–3× melt value including labor and markup
- Melt value — the intrinsic metal value only, ignoring craftsmanship, brand, or gemstones
Reference: gold prices in recent history:
- 2020: ~$1,800/troy oz
- 2022: ~$1,900/troy oz
- 2023: ~$1,980/troy oz
- 2024: $2,000–$2,400/troy oz (record highs)
- 2025: $2,900–$3,300/troy oz
Worked example: 18-karat gold chain, weight: 28 grams. Gold spot price: $2,300/troy oz.
- Troy ounces = 28 ÷ 31.1035 = 0.9003 troy oz
- Purity = 18 ÷ 24 = 0.75
- Melt value = 0.9003 × 0.75 × $2,300 = 0.9003 × $1,725 = $1,553
- Scrap offer (75% of melt): ~$1,165 from a typical gold dealer
- Retail replacement cost: likely $3,000–$5,000 at a jewelry store