How we measure
Everything on this site that is a number comes from a measured source and carries a timestamp. This page sets out where the numbers come from, how they are checked, and exactly how the rankings are calculated. Last reviewed 6 October 2026.
Where the numbers come from
| What | Source | How often |
|---|---|---|
| Spot prices | gold-api.com, in pounds and dollars | Every 10 minutes |
| Live spot on price pages | gold-api.com, shown only within 1% of our stored reading; never stored | About once a minute while a page is open |
| Spot cross-check | metalcharts.org | Roughly once an hour |
| USD to GBP check | European Central Bank reference rate | Daily |
| Dealer prices, stock and buyback | Each dealer's own website | Every hour on weekdays, three times a day at weekends |
| Company records | Companies House | Monthly |
| Trade body membership | The bodies' published member lists | Checked by hand |
Dealer prices are read from each dealer's own public product pages, every hour on weekdays, three times a day at weekends. We collect the price at quantity one and any volume tiers, whether the product is in stock, and the dealer's published buyback ("we buy") price where there is one. Our collector identifies itself honestly in its user agent with a contact address, obeys each site's robots.txt, reads at most one page every two seconds per dealer, and never runs page scripts. Where a dealer has given written permission or a feed, we use that. We do not disguise the collector as a browser.
Spot prices for gold, silver, platinum and palladium are read every 10 minutes from gold-api.com in pounds and dollars. Roughly once an hour the reading is cross-checked against a second feed (metalcharts.org) and the implied GBP/USD rate is checked against the European Central Bank's daily reference rate. A reading is stored only if it passes those checks.
On the spot price pages the figure refreshes about once a minute while the page is open. That live figure, also from gold-api.com, is shown only if it is within 1% of our latest stored reading and that reading is less than 30 minutes old; otherwise the page shows the stored reading. Live figures are never stored, and charts, premiums, rankings and the Index use stored readings only.
Spot charts over 30 days show only readings we have stored ourselves. The 1-year, 10-year and all-time charts add monthly averages before October 2026 from the World Bank Commodity Price Data (CC BY 4.0; gold, silver and platinum; no palladium series), converted to pounds at the Bank of England's monthly average USD/GBP rate (series XUDLUSS). That history is stored separately from our readings, is labelled on every chart, and is never used for premiums, rankings or the Index.
What we hold back
Bad data is worse than no data on a page people use to spend thousands of pounds. These checks run on every reading:
- A spot reading more than 1% from the cross-check source.Rejected
- A GBP conversion more than 1% from the ECB daily rate.Rejected
- A dealer price implying a premium outside plausible bounds for that product (for example below 0% or above 15% on a one-ounce gold coin; wider bounds for small fractional coins and for VAT-inclusive silver).Rejected
- A dealer price that has moved more than 10% since the dealer's previous reading.Rejected pending the next run
- A buyback price that is not below the buy price, or is below half the metal value.Rejected
- Dealer prices older than 4 hours.Shown as delayed, never marked cheapest
Every rejection is logged with its reason. Rejected readings are never shown.
Definitions
- Premium
- Dealer unit price at quantity one ÷ (spot price at the moment the dealer page was read × fine metal weight in troy ounces) − 1. Both timestamps are stored with every reading. For silver, the dealer price is the VAT-inclusive price for new metal delivered to you, and the page says so.
- Cheapest today
- The lowest total for one unit including delivery at the dealer's published rate, among dealers showing the product in stock. The quantity selector on product pages recomputes this using the dealers' volume tiers.
- Round trip (headline)
- (Cheapest buy total anywhere − best published buyback price anywhere) ÷ cheapest buy total. The same-dealer round trip, using that dealer's own buy and buyback prices, is shown for each row.
- Stale
- Spot older than 30 minutes, dealer prices older than 4 hours, or a ranking older than 36 hours is shown as "Prices delayed" with its last-updated time, and the "Cheapest" label is removed. We never show old numbers as current.
The ranking formula
Dealers are ranked daily. Each factor is measured for every dealer, normalised 0 to 1 against the other dealers that day (lowest premium = 1, highest = 0, and so on), multiplied by its weight, and summed. The score is shown out of 10.
| Factor | Weight | What is measured |
|---|---|---|
| Buy price | 40% | Mean premium across the basket products the dealer sells, from the latest reading each day. |
| Buyback | 25% | Mean same-dealer round trip across the basket. A dealer that publishes no buyback price scores 0 on this factor: a buyer cannot see what they would get back, and excluding the factor would reward dealers for not publishing. |
| Costs and terms | 10% | Delivery charge payable on a £1,000 order at the published rate, plus any card surcharge on £1,000, plus £50 if the minimum order exceeds £1,000. |
| Availability | 10% | Share of the day's basket readings that showed the product in stock. |
| Trust | 15% | Years trading from Companies House incorporation date (up to 20 years, half the factor); company active with no overdue filings (30%); LBMA full membership (20%) or LBMA affiliate / BNTA membership (10%). Companies House is checked monthly. |
Because factors are normalised across the dealers ranked that day, a dealer's score can change when a competitor's prices change, not only when its own do. If a factor other than buyback has no data for a dealer (for example no stock observations yet), it is excluded for that dealer and the remaining weights are scaled to 100%. Third-party review scores (Trustpilot and similar) are not part of the score.
The ranking basket: gold 1oz Gold Britannia, Gold Sovereign, 1oz Gold Bar, 100g Gold Bar; silver 1oz Silver Britannia, 1kg Silver Bar.
What we don't do
We don't take commission
We don't earn commission from any dealer today. We may add affiliate links in future. If we do, every one will be marked, and they will never affect rankings. The commission column on every ranking and price table is generated from a single configuration file; the rankings never read it.
We don't place test orders
We have not placed test orders. Nothing here is based on delivery experience, packaging or customer service, because we have not measured those.
We don't use AI to write prices or rankings
Sentences on price pages that contain numbers are filled-in templates: each states a computed fact and its time. No text on this site is written by an AI model.
We don't hide old data
If prices are late, the page says so and stops marking anything as cheapest.
Which dealers
Online UK coin and bar dealers. Vault and trading platforms are a different kind of service and are not ranked against them. We currently measure 11 dealers publicly and are collecting a further 2 privately while we confirm permission to publish their prices. A dealer is added or removed by a human decision, recorded on the corrections and changes log.
Which products
13 products: 1oz Gold Britannia, 1/2oz Gold Britannia, 1/4oz Gold Britannia, 1/10oz Gold Britannia, Gold Sovereign, Gold Half Sovereign, 1oz Gold Bar, 100g Gold Bar, 10g Gold Bar, 1oz Silver Britannia, 1kg Silver Bar, 10oz Silver Bar, 1oz Gold Krugerrand. Weights and fineness are from the mints' and refiners' published specifications. Products are added by a human decision; no page is created automatically.
Use our data
Daily data is published as CSV under a CC BY 4.0 licence. Please credit MetalsAlpha.
Open dataCorrections
When we get something wrong, we fix it and log what changed and when.
Read the corrections log