21k Gold Calculator – 875 Melt Value

Twenty-one karat doesn't fill every U.S. pawn case, but when it shows up — often with an 875 stamp on Middle Eastern or specialty jewelry — wrong-karat shortcuts get expensive fast.

People split the difference between 18K and 22K in their heads. That mental average is not 21 ÷ 24.

This tool locks purity at 87.5% so 21K weight stops borrowing math from its neighbors.

Why 21K gets misquoted

Karat	Purity	Mark
18K	75%	750
21K	87.5%	875
22K	≈ 91.7%	916

From 18K to 21K you pick up 12.5 purity points. From 21K to 22K you only pick up about 4.2. Lumping "high karat" into one rate erases that first jump.

If the piece only says a foreign script mark you can't read, stop and identify before you calculate. Color alone lies.

Working a 21K lot at the counter

Confirm 21K or 875.
Keep it out of 18K and 22K bags.
Weigh dry; note stones and solder-heavy repairs.
Enter weight × 0.875 × spot (same units).
Compare the melt-style line to the offer — ask what purity they used.

Under-plumb risk still applies. Background: half karat under plumb.

Stamp decode: gold hallmark numbers meaning.

EXAMPLE — 8 DWT of 21K

EXAMPLE spot: $4,000 / troy oz (illustrative).

Pure DWT price = 4000 ÷ 20 = $200 / DWT.
21K DWT ≈ 200 × 0.875 = $175 / DWT.

Lot: 8 DWT confirmed 21K scrap.

Melt-style ≈ 8 × 175 = $1,400.

Same 8 DWT as 18K (0.75) → $1,200. Same as 22K (≈0.917) → about $1,467. Knowing you're on 875 parks you in the right seat.

When jewelry resale beats scrap

Clean 21K bridal sets and heavy chains sometimes move as jewelry above melt in the right market. Broken scraps and mismatched singles usually don't.

Don't force a scrap quote on a wearable piece without checking a jeweler bid — and don't romanticize scrap fragments into "estate jewelry" prices. Condition decides. Framing help: scrap vs melt vs resale.

21k gold calculator gold value tips — Visual guide supporting 21k gold calculator — weight, karat, and melt-style estimates.

Related tools and guides

Frequently Asked Questions

What does 875 mean?

Fineness 875 = 87.5% gold — the mark pair for 21K.

Is 21K common in the U.S.?

Less common than 10K/14K in mass retail, but it appears in specialty and imported jewelry. Worth having the right purity ready.

Can I approximate 21K as 22K?

You can — and you'll overstate by a few purity points on every gram. On bigger lots that "few" adds up. Use 0.875.

Does this handle mixed 21K and 22K?

Weigh and price separately. One average purity for two karats is how tickets go sideways.

Grams or DWT?

Either. Many scrap tickets still print DWT. Match the scale.

What if assay comes back under 875?

Solder, repairs, or under-plumb manufacture. Adjust expectations; settlement follows the assay.

Disclaimer

Assumes solid 21K at 87.5% unless you enter another purity. Educational estimates only — not a payout guarantee.