Live melt value for 18K gold — 75% pure gold (750, 18K, 18KT, 18ct)
18K gold contains 18 parts gold per 24 — exactly 75.00% pure gold — with the remaining 25% composed of silver, copper, palladium, or nickel depending on color variant. It is the global standard for fine jewelry and luxury watchmaking, the minimum karat that CIBJO (the World Jewellery Confederation) defines as "fine jewelry," and the near-universal specification of the Swiss watch industry.
18K occupies a distinct position in the karat hierarchy: high enough gold content (75%) to produce the rich, saturated color associated with European fine jewelry; enough alloy (25%) to achieve practical hardness (~120–200+ HV depending on composition) for daily-wear rings, bracelets, and watch cases. Italy — the world's largest gold jewelry exporter by value — uses 18K as its production standard. French and Swiss luxury houses (Cartier, Van Cleef & Arpels, Patek Philippe, Audemars Piguet) specify 18K for virtually all gold components.
| Weight | Pure Gold Content | At $3,000/oz | At $3,200/oz |
|---|---|---|---|
| 1 gram | 0.7500 g | $72.34 | $77.16 |
| 1 DWT (pennyweight) | 1.1664 g | $112.50 | $120.00 |
| 5 grams | 3.750 g | $361.70 | $385.81 |
| 10 grams | 7.500 g | $723.39 | $771.62 |
| 20 grams | 15.000 g | $1,446.78 | $1,543.24 |
| 1 troy oz (31.1g) | 0.7500 ozt | $2,250.00 | $2,400.00 |
| 1 oz avoirdupois (28.35g) | 0.6836 ozt | $2,050.78 | $2,187.50 |
Unlike 14K (where "14K" = 58.333...% repeating and "585" = 58.5%), 18K and 750 are mathematically identical. 18 ÷ 24 = 0.75000 exactly. 750 ÷ 1000 = 0.75000 exactly. This is the only common karat where the US karat fraction and the European millesimal stamp represent precisely the same gold content per gram — there is no rounding discrepancy, no fractional difference between a piece stamped "18K" and one stamped "750." For international trade, estate appraisals, and cross-border sales, 18K gold is the most straightforward karat to value and transact without stamp ambiguity.
All three colors contain exactly 75% gold. The alloying metals control color, hardness, and hypoallergenic properties:
| Color | Gold | Silver | Copper | Other | Notes |
|---|---|---|---|---|---|
| Yellow | 75% | ~12.5% | ~12.5% | — | Balanced Ag/Cu ratio produces the warm saturated yellow of Italian and French fine jewelry |
| Rose | 75% | ~4.5% | ~20.5% | — | High copper against the 75% gold base creates deep, rich rose. Rolex "Everose" adds ~2% platinum for oxidation resistance (patent EP1273669) |
| White (premium) | 75% | ~12.5% | — | ~12.5% Pd | Palladium alloy: naturally hard (~200+ HV), stays white longer, hypoallergenic, less rhodium replating needed |
| White (standard) | 75% | — | — | Ni+Zn blend | Nickel-based: cheaper to produce, requires rhodium plating to appear white; potential allergy concern |
Melt value is identical for all color variants — refiners purchase only the gold fraction at spot price.
The Swiss watch industry produces roughly 95% of luxury watch cases and bracelets in 18K gold, designated by the "750" stamp inside the case back. Major specifications by manufacturer:
Rolex: uses 18K yellow, white, and proprietary Everose gold (18K rose with ~2% platinum for fading resistance — patented alloy EP1273669, introduced in 2005 as a replacement for standard 18K rose). The Submariner Two-Tone uses 18K yellow on a steel case; the Day-Date ("President") is available exclusively in 18K or platinum. Patek Philippe: 18K yellow, rose, and white gold across the Calatrava, Nautilus, and Aquanaut lines. Audemars Piguet: 18K across the Royal Oak line; their "Frosted Gold" is 18K treated with the Carolina Bucci hammering technique. Cartier: 18K yellow, rose, and white gold for Tank, Santos, and Panthère cases. When buying, selling, or insuring a luxury watch, the "750" hallmark is the gold content you're paying for — use the live calculator above with the total gold component weight to find melt value independent of brand premium.
CIBJO (Confédération Internationale de la Bijouterie, Joaillerie et Orfèvrerie) — the World Jewellery Confederation, the international body whose standards are adopted by auction houses, national trade associations, and the GIA — defines "fine jewelry" as requiring precious metals of at least 18K (750 fineness). Items in lower karats are classified as "jewelry" without the "fine" qualifier. This institutional definition matters practically: Christie's, Sotheby's, and Bonhams catalog estate lots as "fine jewelry" only when gold components meet the 18K threshold. Insurance appraisers using USPAP standards similarly apply this distinction. When a piece you own or are considering buying is described as "fine jewelry," the minimum implied gold content is 18K.
No. Under IRC Section 408(m)(3)(B), gold held in a self-directed IRA must meet a minimum fineness of .995 (99.5% pure). At 75% purity, 18K gold is far below this threshold. No 18K jewelry, chains, designer pieces, or watch components are IRA-eligible regardless of weight, brand, or value. The sole IRA-eligible gold items are investment-grade bullion bars (≥.995 fineness) and specific government-minted coins listed in the statute — American Gold Eagles are a statutory exception despite being 22K/91.67% under §408(m)(3)(A). Consult a qualified tax advisor before making any IRA-related precious metals decisions.
Standard stamps: 750 (European millesimal — used globally in fine jewelry and Swiss watches), 18K, 18KT (T = troy), 18ct (British/Australian). Letter suffixes after the karat indicate non-solid gold: 18K GF = gold-filled; 18K GP = gold-plated. A bare "750" or "18K" with no suffix = solid gold throughout. In addition to the fineness stamp, UK pieces carry an assay office hallmark (London Goldsmiths' Hall leopard's head, Birmingham anchor, Edinburgh castle, Sheffield Yorkshire rose). Swiss watch case backs carry the "750" stamp plus the manufacturer's poinçon de maître (maker's mark) under Swiss federal hallmarking law.
| Karat | Purity | Stamp | Hardness (HV) | "Fine Jewelry"? |
|---|---|---|---|---|
| 24K | 99.99% | 999 | ~25 HV | Yes (bullion) |
| 22K | 91.67% | 916 | ~90 HV | Yes |
| 18K | 75.00% | 750 | ~120–200+ HV | Yes — CIBJO minimum |
| 14K | 58.33% | 585 | ~120–150 HV | No (jewelry) |
| 10K | 41.67% | 417 | ~120 HV | No (jewelry) |
| 9K | 37.50% | 375 | ~120 HV | No (jewelry) |
Live melt value is in the calculator above, updated every 60 seconds. Formula: spot price ÷ 31.1035 × 0.75. At $3,200/oz: $77.16/gram. At $3,000/oz: $72.34/gram. At $2,800/oz: $67.52/gram. Multiply by your weight in grams for total melt value.
Yes — and this is unique among common karats. 18 ÷ 24 = 0.75000 exactly. 750 ÷ 1000 = 0.75000 exactly. Unlike 14K (where "14K" = 58.333...% repeating while "585" = 58.5%), there is zero rounding discrepancy between the US karat stamp and the European millesimal stamp for 18K. A piece marked "18K" and one marked "750" contain precisely identical gold content per gram. This makes 18K the cleanest karat for international cross-border trade and estate appraisals.
18K is the Swiss luxury watch standard because it balances high gold content (75%) with practical hardness (~120–200+ HV) for daily-wear cases and bracelets. Rolex uses 18K yellow, white, and their patented Everose (18K rose + ~2% platinum, EP1273669, introduced 2005 to prevent the fading of standard rose gold). Patek Philippe, Audemars Piguet, and Cartier all specify 18K across their gold lines. The "750" stamp inside a watch case back is the gold content you're paying for — calculate its melt value above with the gold component's weight.
CIBJO (the World Jewellery Confederation) defines fine jewelry as items made with precious metals of at least 18K (750 fineness) and genuine gemstones. This is the standard adopted by Christie's, Sotheby's, Bonhams, and the GIA. Items in 14K or 10K are categorized as "jewelry," not "fine jewelry," under CIBJO standards. When a piece is sold or appraised as "fine jewelry," 18K is the minimum gold content that designation implies.
All contain 75% gold. 18K yellow: ~75% Au + ~12.5% Ag + ~12.5% Cu — balanced ratio produces the saturated warm yellow of Italian and French fine jewelry. 18K rose: ~75% Au + ~4.5% Ag + ~20.5% Cu — rich deep rose; Rolex Everose adds ~2% platinum for oxidation resistance. 18K white (premium/palladium): ~75% Au + ~12.5% Pd + ~12.5% Ag — naturally hard (~200+ HV), hypoallergenic, stays white longer, less rhodium replating needed. 18K white (standard/nickel): 75% Au + nickel/zinc blend — cheaper but potential allergen. All have identical melt value.
No. IRC Section 408(m)(3)(B) requires gold in a self-directed IRA to have minimum fineness of .995 (99.5% pure). At 75% purity, 18K gold — including fine jewelry, Cartier pieces, and designer items — does not qualify for IRA inclusion regardless of value. The only IRA-eligible gold is investment-grade bullion bars at ≥.995 fineness and specific government-minted coins (American Gold Eagles are a statutory exception despite being 22K/91.67%). Consult a qualified tax advisor for IRA guidance.
Calculate melt value first — then research the brand. Generic 18K jewelry typically sells close to melt. But Cartier, Tiffany, Van Cleef & Arpels, Bulgari, and Patek Philippe pieces routinely sell at auction or on resale platforms (1stDibs, Chrono24 for watches) at significant premiums above melt. A Cartier Love bracelet in 18K may trade at 150–300%+ of gold melt value. Check recent sold listings before accepting any scrap offer on branded or signed pieces.
Compare the live price per gram across all common gold purities at today's spot price.
| Karat | Purity | Common Use | |
|---|---|---|---|
| 24K Gold | 99.99% | Bars, bullion coins | 24K Gold Price Per Gram → |
| 22K Gold | 91.67% | Krugerrands, Eagles | 22K Gold Price Per Gram → |
| 18K Gold | 75.00% | Fine jewelry | 18K Gold Price Per Gram → |
| 14K Gold | 58.33% | US jewelry standard | 14K Gold Price Per Gram → |
| 10K Gold | 41.67% | Entry-level jewelry | 10K Gold Price Per Gram → |