Price source
Live gold prices come from an institutional foreign-exchange market data feed for XAU/USD, using the midpoint between the current bid and ask.
Data & transparency
Methodology
Every estimate on this site comes from a published formula and a live market feed — here is exactly how the numbers are produced, updated, and rounded.
Reviewed and updated
Update cadence
The spot price refreshes every 60 seconds while the page is open. Every price is shown with its timestamp.
Independence
We do not buy or sell gold and earn nothing from your result, so the estimate has no reason to lean high or low.
How a live price becomes your estimate
- 1The live XAU/USD quote is fetched and the bid–ask midpoint is taken as the spot price per troy ounce.
- 2Your weight entry is converted to troy ounces (1 ozt = 31.1035 g, 1 dwt = 1.5552 g, 1 tola = 11.6638 g, 1 baht = 15.244 g).
- 3Nominal purity is calculated as karat ÷ 24: for example, 18K uses 0.75 and 14K uses 14/24. The 24K setting uses a documented 0.999 convention.
- 4The result is multiplied by the price and, if selected, by a dealer payout percentage (90%, 80%, or 70%).
To put this into practice, use Gold Value Calculator, check the assumptions with Gold Price Per Gram, and compare the result in Scrap Gold Calculator.
Live prices, timeouts, and the cached-price notice
Price requests time out after 8 seconds. If the live feed is briefly unreachable, the calculator falls back to the most recent successfully fetched price and tells you it is showing cached data rather than silently displaying a stale number. When no price has ever been fetched and the feed is down, the calculator shows an error instead of inventing a value — you can always continue with the manual price field.
Published reference prices
Static HTML includes a quote captured when the site is built, with an absolute UTC capture time and the provider name. It is a reference price and does not change until the next deployment. Browser requests replace it with current data when available. A failed build-time feed produces an unavailable state rather than a fabricated price.
Currency conversion
The feed is quoted in US dollars. ExchangeRate-API provides USD-based conversion rates when the page loads. The build also captures reference rates and their timestamp so international pages contain a sourced currency estimate before JavaScript runs. If live rates fail, the published reference rate remains in use; without one, the calculator labels its August 2026 fallback rate. These are separate from official local retail or buyback rates. Enter a current local spot quote per troy ounce in the manual field to use your own price basis.
Purity ratios and rounding
The formula uses karat divided by 24 at full numeric precision, except the 24K setting, which uses 0.999. Millesimal fineness is a separate notation: a 585 stamp states 58.5%, while nominal 14K is about 58.333%. Similarly, 916 states 91.6%, while nominal 22K is about 91.667%. For exact settlement, use an assay or tested fineness agreed with the buyer. Monetary figures are rounded for display; intermediate calculations retain their precision.
What this tool is not
Estimates here are informational melt-value calculations, not appraisals, buyer offers, insurance valuations, or financial advice. Real offers depend on testing, refining costs, local demand, and dealer margin — which is why the payout selector exists. Corrections and questions are welcome at support@goldcalculator.co.
Primary sources and further reading
We use primary or official references for measurement, purity, hallmark, and coin specifications. Market prices remain time-sensitive and are timestamped separately.
- Swissquote — XAU/USD public quote feed — The bid and ask market data used to calculate the displayed midpoint reference price.
- NIST — Precious Metals Conversion Information — Official troy-ounce, gram, pennyweight, and grain conversion factors.
- Federal Trade Commission — Buying Platinum, Gold, and Silver Jewelry — Consumer guidance on karat descriptions, solid gold, and plated or filled jewelry.
Common questions
Why does your price differ slightly from other gold sites?
Sites can quote the bid, the ask, or the midpoint, and refresh at different moments. We use the bid–ask midpoint refreshed every 60 seconds, so small differences from sites quoting one side of the spread — or an older tick — are normal.
What does the "cached price" warning mean?
It means the last live fetch failed and you are seeing the most recent good price with its timestamp. The calculator retries automatically every minute; you can also enter a manual price at any time.
Can I verify the calculation myself?
Yes. Weight in troy ounces × karat purity ratio × price per troy ounce × payout percentage. Every input the calculator used — price, timestamp, purity, and payout — is shown alongside the result.
Open the calculator
Enter weight, purity, currency, and payout percentage in the main tool.