In the UK a 1oz gold bar (31.1g) almost always gives you the lowest price per gram of the three sizes, and a 1g bar the highest. Making, packaging and certifying a tiny bar costs nearly as much as a larger one, so the fixed costs are spread over far less gold. A 10g bar sits in between: dearer per gram than an ounce, but much cheaper per gram than a 1g bar.
What you actually pay for
The price of any bar is the value of the fine gold inside it plus a premium. The premium covers refining, minting or casting, packaging, an assay card, insurance, delivery and the dealer’s margin. Much of that is a fixed cost per item: the blister pack on a 1g bar costs roughly what the one on a 1oz bar does.
So the premium, expressed as a percentage of the gold value, falls as the bar gets heavier. The same thing happens in reverse when you sell. Dealers usually buy small bars back at a bigger discount to the gold price than they offer for ounces and larger bars.
A worked example with illustrative numbers
Assume, purely for illustration, that fine gold costs £100 per gram. The premiums below show the principle and are not real quotes. For today’s figures see live UK gold prices.
| Bar | Gold content | Illustrative premium | Illustrative price | Price per gram |
|---|---|---|---|---|
| 1g | 1g | 15% | £115 | £115 |
| 10g | 10g | 5% | £1,050 | £105 |
| 1oz | 31.1g | 3% | £3,203 | £103 |
In this example, buying 31.1g of gold as 31 one-gram bars would cost about £3,577. Three 10g bars plus a 1g bar would cost about £3,266. A single 1oz bar would cost about £3,203. The difference comes entirely from the premiums.
Don’t forget the spread
The spread is the gap between a dealer’s selling price and its buy-back price for the same product. It is what you would lose if you bought and immediately sold. Small bars tend to have wider spreads in percentage terms because the premium you pay is higher and the buy-back discount is bigger.
- Look at the buy and sell prices for exactly the same product, not just the headline price.
- Compare several dealers on the UK bullion dealers page, because both sides of the spread vary.
- The shorter you expect to hold the gold, the more the spread matters.
When a 1g or 10g bar makes sense
Smaller bars are not a “wrong” choice. They simply cost more per gram. People choose them deliberately when:
- The budget is small. If you have a few hundred pounds, an ounce may simply be out of reach.
- Flexibility matters. Several 10g bars let you sell part of your holding without selling all of it.
- It is a gift. A 1g or 5g bar is a common christening, birthday or wedding present rather than an investment.
- You buy regularly. Small bars let you buy in small monthly amounts. An alternative is to save the cash and buy a larger bar less often.
When the 1oz bar is the better fit
If the aim is the most gold for your money, the ounce usually wins among these three sizes. It is the most widely traded investment format in the world and almost every UK dealer quotes a buy-back price for it.
Larger bars, such as 100g, 250g or 1kg, usually carry an even lower premium per gram. The trade-off is a much bigger outlay, and when you sell you have to sell the whole bar at once.
VAT and Capital Gains Tax in the UK
Gold bars of at least 995 fineness, in a weight accepted by the bullion markets, count as investment gold and are exempt from VAT. That applies to 1g, 10g and 1oz bars alike, so VAT does not change the comparison.
Capital Gains Tax is different. HMRC treats UK legal tender coins such as the Sovereign and the Britannia as sterling currency, so gains on them are exempt from CGT. Gold bars of any size are chargeable assets. Gains above the annual exempt amount (£3,000 for 2025–26) are taxed at 18% or 24% depending on your income. Check the current figures on gov.uk before relying on them. Some buyers therefore compare a 1oz bar with a 1oz Britannia coin, which usually costs a little more but sits outside CGT.
What to check, whatever the size
- Fineness. Investment bars are normally 999.9 fine.
- Maker. Bars from refiners on the LBMA Good Delivery list are the easiest to resell.
- Packaging and certificate. Keep the assay card sealed. A damaged pack can lower the buy-back price.
- Price per gram. Divide the total price, including delivery, by the weight to compare sizes fairly. The gold calculator shows the metal value for any weight.
Storage and delivery
Size also affects hidden costs. Ten 1g bars take up more room and are harder to keep track of than one 10g bar. Online delivery and insurance are often a flat fee, which weighs more heavily on a small order. If you rent a safe deposit box or use a vault, the fee usually depends on value or space rather than the number of bars.
Bottom line
The premium per gram falls as bar size rises. Of the three sizes, the 1oz bar usually has the lowest price per gram, the 1g bar the highest, and the 10g bar sits in between. All three are VAT-free as investment gold, and all are subject to CGT, unlike Sovereign and Britannia coins. Smaller bars offer flexibility and a lower entry price in exchange for a higher cost per gram and a wider spread.
Sources: GOV.UK – CGT rates and allowances · HMRC Capital Gains Manual CG78305 · LBMA – Good Delivery
This is general information, not tax or investment advice.
Frequently asked questions
Which gold bar is the best value per gram: 1g, 10g or 1oz?
Usually the 1oz bar, because the fixed costs of making and packaging it are spread over 31.1g of gold. A 1g bar normally has the highest price per gram.
Is it worth buying 1g gold bars?
They cost more per gram and have wider spreads, but they need only a small budget and are popular as gifts. As a way of building up gold they are more expensive than larger bars.
Do I pay VAT on a 1g gold bar in the UK?
No, provided it is at least 995 fine and qualifies as investment gold. The exemption applies regardless of the bar's size.
Are gold bars exempt from Capital Gains Tax?
No. Gold bars are chargeable assets for CGT. Sovereigns and Britannias are exempt because HMRC treats them as UK legal tender.
