Old Gold Exchange Calculator
A customer brings in old jewellery and wants something new for it. This works out both halves of that counter conversation — what the old gold is genuinely worth to you, what the new piece costs them — and nets one against the other, so the balance payable can be shown line by line instead of arrived at in someone's head.
Old Gold Exchange Calculator
Value the old gold a customer brings in, price the new piece they are buying, and see exactly what is left to pay — with a separate buy-back rate and selling rate, because they are not the same figure.
One currency for the whole exchange — the balance subtracts one side from the other, and no exchange-rate conversion is applied here.
Enter the old gold's gross weight to see its net metal weight and the credit it earns.
Enter the new piece's gross weight to see its net metal weight and full quote.
Settlement
Complete both sides — the old gold and the new piece — to see the balance payable. Nothing is estimated from one side alone.
How this is calculated
Accepted exchange credit = the old gold's net metal weight × its purity fraction × your buy-back rate, less your deduction percentage, less your flat melting or refining fee. The stone weight comes off before any purity math, so you never credit gold the piece does not contain.
New jewellery total is the same full quote the Quote Builder produces — metal value, wastage, making charge, material cost, margin and tax, in that order.
Balance payable = new jewellery total − accepted exchange credit. If the credit is larger, the balance is zero and the surplus is shown separately as remaining exchange credit — never as a negative balance.
The order of operations, stated in full
Every step below is shown with its own subtotal, so the figures can be checked against your own practice rather than trusted as one final number.
- Net old-gold weight = gross old-gold weight − stone / non-gold weight
- Fine gold weight = net old-gold weight × karat fraction
- Old-gold metal value = fine gold weight × your buy-back rate
- − Deduction = deduction % of the old-gold metal value
- − Melting / refining fee = the flat amount you enter
- = Accepted exchange credit
- New jewellery total = the full quote for the new piece, including any tax
- Balance payable = new jewellery total − accepted exchange credit
- If the credit is larger, balance payable is zero and the surplus is shown as remaining exchange credit
Why there are two rates, not one
The rate a shop pays for old gold and the rate it sells at are different commercial figures, and the gap between them is the shop's own decision. This calculator therefore keeps them as two separate inputs, each with its own price source, and never derives one from the other. No dealer spread, buy/sell margin or discount to the reference price is assumed anywhere. If your shop genuinely uses the same rate both ways, enter it twice — deliberately, rather than having it assumed for you. Both sides share one currency, because the balance subtracts one from the other and no exchange-rate conversion is performed here.
When the old gold is worth more than the new piece
The balance payable is shown as zero and the surplus appears separately as remaining exchange credit. A negative balance is never displayed, because “you owe minus four hundred” is not a figure anyone hands a customer — but the surplus is never quietly dropped either. What happens to it, whether it is paid out, held as credit or put toward something else, is between you and the customer; this calculator does not pay it, carry it forward or record it anywhere. Separately, if the deductions you enter come to more than the old gold is worth, no credit is produced at all and the calculator says so plainly rather than turning it into a charge.
How this differs from the other tools
The Scrap Gold / Melt Value Calculator values old gold with a deduction and a fee, but it treats the weight you enter as entirely metal — for a stone-set piece that over-credits the customer — and it has no purchase side at all. The Jeweller Quote Builder prices the new piece and is reused here in full, but on its own it has no concept of anything the customer brings in. Buyer Offer vs Melt compares an offer already received against melt value; it computes neither a payout nor a purchase. What is new here is the settlement itself — netting an independently valued buy side against an independently valued sell side.
What this calculator does not do
It assumes no deduction, refining fee, wastage, making charge, material cost, margin or tax rate for any market — every one of them is yours, and a blank field contributes exactly zero. It applies no discount. It handles one old piece against one new piece, not a mixed-karat lot; for several old items at different karats, total them in the Mixed-Karat Lot Calculator first. It does not fabricate a Gold price — when no verified platform reference is available it says so and still shows the weights, which need no market data. There is no customer record, job number, invoice, saved exchange or printable document: this is a calculator, and nothing you enter is stored anywhere. The result is arithmetic on your own figures, not an appraisal or a binding offer.