Gold calculator — value by karat, making charge & bullion

The gold value formula (with worked examples)

Gold jewellery is never priced at the pure-gold rate. Karat tells you how much of the piece is actually gold: 24K is pure, 21K is 21/24 = 87.5% gold, 18K is 18/24 = 75%. So the metal value is always the gram price scaled by that fraction. The gold calculator applies it automatically once you enter the weight and pick the karat.

Worked example: at a 24K price of 4,000 per gram, a 15-gram 21K chain holds 15 × 21/24 = 13.125 grams of pure gold, worth 13.125 × 4,000 = 52,500. An 18K version of the same weight would be 15 × 18/24 = 11.25 grams pure, so 45,000. Lower karat, lower value — because there is less gold in the same weight. The calculator shows the metal value first, then lets you add costs, so you always see where the number comes from.

Making charges (المصنعية) — what you pay above the metal

The price a jeweller quotes is more than the melt value. On top of the metal, you pay a making charge — المصنعية — for the labour and design of turning raw gold into a finished piece. It is usually a fixed amount per gram, and it varies by workmanship: a plain wedding band carries a small charge, an intricate necklace a much larger one.

This matters in two directions. When buying, the making charge is real money you will not get back — an ornate piece can cost far more than its gold content. When selling old jewellery, most dealers pay you the metal value only and drop the making charge entirely. The gold calculator lets you enter a making charge per gram so the total you see matches the shop counter, not just the raw metal figure — and you can compare buy total against likely resale.

Convert weight across karats without losing value

A common question at the counter: "I have 100 grams of 21K — how much 18K is that?" You are really asking how to keep the same amount of pure gold at a different purity. Since lower karat means less gold per gram, you need more grams. The karat converter does the math: 100g of 21K holds 87.5g of pure gold, and 87.5g ÷ 0.75 ≈ 116.7g of 18K carries the same pure gold.

Here is the step-by-step, and the expected result. First, pick your source karat and weight (100g, 21K). Second, choose the target karat (18K). Third, read the converted weight (≈116.7g) — that heavier number is not a trick; it is the weight of 18K gold that contains exactly your original pure gold. The tool also shows the shared value, so you can confirm nothing was gained or lost in the swap.

Does the value change when you convert karats?

No — and this is the single most misunderstood point in gold math. Converting 100g of 21K to ≈116.7g of 18K does not change what the gold is worth, because both hold the same 87.5g of pure gold. The extra grams in the 18K figure are the added alloy metals, which have negligible value. The metal value is identical before and after; only the total weight and the karat label change.

This is why the karat converter is built to conserve pure-gold content rather than just flip a number. It is also the basis for the zakat use case: when you own jewellery in mixed karats, you unify everything to one karat first, then apply the threshold. If that is your goal, the zakat calculator takes it from there with today's nisab, and the gold-silver prices explainer covers how per-karat gram prices are set.

Bars, the gold pound and sovereigns

Bullion is priced differently from jewellery because it carries little or no making charge — you are paying for weight and purity, plus a small dealer premium. Standard bars run from 5g to 100g and up. The gold pound (الجنيه الذهب) common in Egypt is 8 grams of 21K, which holds 7 grams of pure gold; the half and quarter pound scale down from there. A British sovereign contains 7.32 grams of fine gold.

To price any of these, multiply the pure-gold content by the current 24K gram rate: a gold pound is worth 7g × the 24K price, plus the coin premium. The bullion and coins reference lists bars, the gold pound, half and quarter pound, sovereign and ounce coins by country from live rates, so you can compare a coin's asking price against its metal value before you buy. For the raw per-gram numbers behind all of it, open gold prices.

Scrap gold: what your old jewellery is really worth

Selling broken chains, single earrings or outdated pieces? Scrap value is pure metal value with no making charge added back — dealers pay for the gold, not the craftsmanship you originally paid extra for. Weigh the lot, note the karat stamp (21K, 18K), and run it through the gold calculator with the making charge left at zero to see the honest metal figure.

Two realities to expect. First, dealers usually pay slightly under the live 24K rate to cover their margin and refining, so treat the calculator's metal value as your ceiling, not the exact cash offer. Second, mixed-karat lots should be weighed and calculated per karat, or unified with the karat converter first. Knowing the number before you walk in stops you from being lowballed — you can quote the metal value yourself.

Frequently asked questions