Gold purity and karats: what 10K, 14K, 18K, 22K and 24K mean

Karats measure the gold fraction

Karats express gold as parts out of 24. Nominal 14K is 14/24, approximately 58.33%; 18K is 18/24, or 75%. Fineness expresses a proportion per thousand: 750 means 75% gold, while .9999 denotes 99.99%. A higher number means more gold in the same eligible alloy weight, not necessarily a higher resale value for two different finished pieces.

Keep a karat calculation distinct from a declared fineness preset. Meridian’s calculator uses .585 for its common 14K preset and .417 for 10K. These are not the exact fractions 14/24 and 10/24. A 585 fineness mark declares 58.5%, while nominal 14K arithmetic gives about 58.33%. Record the actual mark and ask which tested fineness supports a transaction.

A hallmark is evidence, not proof

Hallmarks help classify an item, but stamps can be missing, worn, repaired or counterfeit. Solder, clasps, stones, springs and filled components can also differ from the main alloy.

A professional process uses the hallmark to choose a test, then reconciles the result with weight, construction and visual inspection. When the economics are material, non-destructive screening may be followed by a more conclusive method.

Calculate contained gold

Start with the weight of the eligible gold alloy—not a whole jewellery box, packaging or stones. Multiplying that alloy weight by the purity fraction estimates fine-gold content. Multiply fine-gold grams by a dated CAD pure-gold reference per gram to estimate metal value. Do not apply the purity fraction again if your input weight is already fine-gold weight.

The following example is hypothetical, not a current gold price or Meridian offer. A ring weighs 17.4 g gross. Assume a qualified assessment establishes 1.8 g of stones and other excluded material, leaving 15.6 g of eligible alloy. Using nominal 14K for this example, 15.6 × 14/24 = 9.10 g of fine gold. At an invented C$120 per fine gram, metal reference value is C$1,092.

Why your calculator can differ from a buyer’s result

The C$3.12 difference between the two purity assumptions above is arithmetic, not evidence that either party is dishonest. A different eligible weight, tested fineness or reference time can matter much more. Ask the buyer to show those inputs rather than comparing two unexplained totals.

Non-gold components should not disappear into an unexplained deduction. Ask how stones and mixed parts were handled, whether any removal is destructive, and what consent is required before work begins. Do not dismantle a valuable or potentially collectible piece at home to approximate the example’s excluded weight.

Measurement Canada advises sellers using a weight-based transaction to look for the scale’s inspection sticker and request its latest inspection certificate. That addresses measurement; it does not establish purity, a fair price or the value of stones.

Metal value is not automatically the amount you receive

A buyer’s final amount can reflect testing, refining or resale costs and its margin. A wearable signed piece, unusual coin or collectible item may instead warrant a separate resale assessment. Compare those routes before agreeing to treatment as scrap. The calculator does not price design, provenance, stones or rarity.

For a useful comparison, write down four numbers: pure-metal reference, eligible fine-metal content, the offered net dollars, and net dollars as a percentage of that reference. Then record what remains conditional on verification. Meridian provides research and indicative tools; the calculation does not book an assessment or create a purchase offer.

• Keep different hallmarks and product types separate.
• Record the CAD reference, unit and timestamp.
• Ask for every fee and deduction in writing.
• Compare the final payable amount, not only a percentage headline.