Gold Bar Weights & Sizes: Complete UK Guide
From 1-gram wafers to 12.4kg LBMA Good Delivery bars, this guide covers every gold bar size available to UK buyers. Live prices, premiums by weight, and which size gives you the best value.
Quick Answer: How Much Does a Gold Bar Weigh?
12.4 kg
400 troy oz — LBMA Good Delivery
31.1 g
1 troy ounce — best balance
1 g
Novelty size — high premiums
Every Gold Bar Size Explained
Gold bars are manufactured in standardised sizes from 1 gram to 400 troy ounces. All investment-grade bars are at least 999.9 fineness (24 carat, 99.99% pure gold), except the LBMA Good Delivery standard which requires a minimum of 995 fineness.
| Size | Fineness | Dimensions | Premium | Approx. Value |
|---|---|---|---|---|
| 1 gram | 999.9 | 8mm x 15mm x 0.4mm | 15-25% | £122 |
| 5 gram | 999.9 | 14mm x 23mm x 1mm | 8-15% | £610 |
| 10 gram | 999.9 | 18mm x 31mm x 1.2mm | 5-10% | £1,220 |
| 20 gram | 999.9 | 22mm x 38mm x 1.5mm | 4-7% | £2,441 |
| 1 troy ounce (31.1g)Popular | 999.9 | 24mm x 42mm x 2mm | 3-5% | £3,796 |
| 50 gram | 999.9 | 27mm x 47mm x 2.5mm | 3-5% | £6,102 |
| 100 gramPopular | 999.9 | 31mm x 55mm x 3mm | 2-4% | £12,203 |
| 250 gram | 999.9 | 40mm x 70mm x 6mm | 2-3% | £30,508 |
| 500 gram | 999.9 | 47mm x 83mm x 8mm | 1.5-2.5% | £61,015 |
| 1 kilogramPopular | 999.9 | 53mm x 116mm x 9mm | 1-2% | £122,030 |
| 400 troy ounces (~12.4kg) | 995+ | ~255mm x 81mm x 37mm | 0.5-1% | £1,518,224 |
Values at spot price (£122.03/g). Actual purchase prices include dealer premiums shown. Updated 2026-03-15.
The Premium Rule: Bigger Bars = Lower Cost Per Gram
The most important thing to understand about gold bars is the relationship between size and premium. Smaller bars cost more per gram because the manufacturing, assaying, packaging, and shipping costs are spread across less gold.
A 1g bar at 20% premium means you need gold to rise 20% just to break even. For small budgets, gold sovereigns (3-5% premium, CGT-free) are far better value.
A 1kg bar at 1.5% premium needs just a 1.5% price rise to break even. However, you can't sell half a bar — larger bars mean less flexibility.
Premium Impact — Real Numbers
Based on today's gold price of £122.03/g:
Which Gold Bar Size Should You Buy?
Skip Bars — Buy Sovereigns Instead
At this budget, bar premiums are too high. A gold sovereign gives you 7.32g of pure gold at a 3-5% premium AND is CGT-free. A 5g bar at 10%+ premium with CGT liability is strictly worse.
1oz Bar (31.1g) or Multiple Sovereigns
The 1oz bar is the sweet spot for retail investors — low premiums (3-5%) and universally recognised. However, multiple sovereigns at similar premiums give you CGT-free gains and more flexibility to sell in portions.
100g Bar — Best Premium-to-Accessibility Ratio
The 100g bar carries 2-4% premiums and is small enough to store easily and sell without difficulty. This is the most popular bar size for UK investors building a meaningful gold position. Consider mixing with sovereigns for CGT diversification.
250g or 500g Bar + Sovereigns
At this level, consider a mix: one or two larger bars for the low premiums, plus sovereigns for the CGT-free allowance. This gives you both cost efficiency and tax efficiency.
1kg Bar — Lowest Premium Available
The 1kg bar has the lowest premium of any retail gold product (1-2%). At this investment level, vault storage is recommended. The 400oz LBMA Good Delivery bar is available but typically only through institutional channels.
Gold Bars vs Coins: The Tax Question
This is the crucial decision for UK gold investors. Gold bars have lower premiums, but coins can save you far more in tax.
| Feature | Gold Bars | Sovereigns | Britannias |
|---|---|---|---|
| VAT | Free | Free | Free |
| CGT on Profits | 18-24% (above £3k) | Exempt | Exempt |
| Premium (typical) | 1-5% | 3-8% | 3-6% |
| Purity | 999.9 (24ct) | 916.7 (22ct) | 999.9 (24ct) |
| Flexibility | All or nothing | Sell one at a time | All or nothing (1oz) |
| Best For | Large positions, low premium | Tax-free gains, flexibility | Tax-free, 1oz standard |
The Break-Even Point
A sovereign's premium is typically 2-3% higher than a similar-weight bar. But CGT on a bar is 18-24% of gains above £3,000. On a £10,000 gain, a bar costs you up to £1,680 in CGT — far more than the extra £50-100 you'd pay in sovereign premiums. For most UK investors with gains above £3,000, sovereigns win despite the higher premium. See our CGT-free gold guide for the full breakdown.
The LBMA Good Delivery Bar: The "Standard" Gold Bar
When people picture a gold bar, they usually imagine the LBMA Good Delivery bar. These are the bars held by central banks and traded on the London gold market.
Who trades them: Central banks, institutional investors, LBMA members, and large bullion banks. Not typically available to retail investors.
Where they're stored: Primarily in London vaults (Bank of England, JP Morgan, HSBC, Brink's) and in central bank reserves worldwide.
Can I buy one? Technically yes, through specialist dealers. But the price (£1,518,224+), storage requirements, and resale logistics make it impractical for most investors.
Approved refiners: Only bars from LBMA-accredited refiners (PAMP, Metalor, Umicore, Argor-Heraeus, etc.) qualify.
Trusted Gold Bar Refiners
When buying gold bars, the refiner matters. Bars from LBMA-accredited refiners command better resale prices and are accepted by all dealers without additional assaying.
Top-Tier Refiners (Best Resale)
- ✓PAMP Suisse — Swiss, premium brand, Fortuna design
- ✓Metalor — Swiss, major LBMA refiner
- ✓Umicore — Belgian, widely recognised in UK
- ✓Argor-Heraeus — Swiss, institutional standard
- ✓The Royal Mint — UK government mint
What to Check on Any Bar
- →Refiner name and logo clearly stamped
- →Weight (in grams or troy ounces) engraved
- →Fineness mark (999.9 or 9999)
- →Unique serial number
- →Assay certificate (sealed bars come with one)
Avoid Unknown Refiners
Bars from non-LBMA refiners may be genuine gold, but they can be harder to resell. Some dealers will require independent assaying before buying them, adding cost and delay. Stick to bars from the refiners listed above for the best liquidity.
Storing Gold Bars
Bars require the same security considerations as coins, but their higher value per unit makes proper storage even more important.
Small bars (under 100g)
A quality home safe (BS EN 1143-1 rated, bolted down) is usually sufficient. Ensure your home contents insurance covers the value — most standard policies cap precious metals at £1,000-2,000 without a specialist rider.
Medium bars (100g-500g)
Consider a bank safe deposit box (£100-300/year) or specialist vault storage. At these values, the annual storage cost is a small fraction of the bar's worth and the security is far superior to home storage.
Large bars (1kg+)
Professional vault storage is strongly recommended. Services like The Royal Mint's vault or BullionVault's allocated storage provide full insurance, regular auditing, and easy liquidation. Typical cost is 0.5-1% of value per year.
Keep all assay certificates and purchase receipts separate from the bars themselves. These documents prove authenticity and ownership for insurance claims and resale. See our full gold storage guide for detailed comparison of all storage options.
Frequently Asked Questions
How much does a gold bar weigh?
Gold bars come in sizes from 1 gram to 400 troy ounces (12.4kg). The most common retail sizes are 1oz (31.1g), 100g, and 1kg. The "standard" LBMA Good Delivery bar seen in bank vaults and films weighs approximately 12.4kg and is worth around £1,518,224 at current prices.
What size gold bar should I buy?
The 1oz (31.1g) bar offers the best balance of low premiums and accessibility for most budgets. The 100g bar is ideal for investments of £5,000-8,000. For smaller budgets, gold sovereigns are better value than small bars. For large investments (£50,000+), the 1kg bar offers the lowest premiums.
Do you pay tax on gold bars in the UK?
Gold bars are VAT-free but subject to Capital Gains Tax on profits above the £3,000 annual allowance (18% basic rate, 24% higher rate). Unlike gold sovereigns and Britannias, bars are not UK legal tender and therefore not CGT-exempt. For tax-free gold investment, see our sovereign buying guide.
How much is a 1kg gold bar worth?
At today's gold price of £122.03/g, a 1kg bar's spot value is £122,030. With a typical 1-2% dealer premium, expect to pay £123,250-£124,471. Use our gold calculator for live pricing.
What is an LBMA Good Delivery bar?
The LBMA (London Bullion Market Association) Good Delivery standard defines bars weighing 350-430 troy ounces (~12.4kg), at least 995 fineness, from accredited refiners. These bars are the international trading standard used by central banks and bullion banks. Most retail investors buy smaller bars from the same LBMA-approved refiners.
Are smaller gold bars worth buying?
Bars under 10g carry premiums of 8-25%, making them poor investments. For small budgets, gold sovereigns (7.32g pure gold, 3-5% premium, CGT-free) offer far better value. The smallest bar that makes investment sense is the 1oz (31.1g) at a 3-5% premium.
Calculate Your Gold Bar's Value
Use our calculator to find live prices for any weight of gold
Related Guides
CGT-free, VAT-free, and the most tax-efficient way to own physical gold.
Read Guide →Troy ounces vs grams vs pennyweights — master the weight units dealers use.
Read Guide →Compare dealers, platforms, and mints for coins and bars.
Read Guide →Sources and References
Bar specifications from LBMA Good Delivery Rules for Gold and Silver Bars.
LBMA Good Delivery List:lbma.org.uk
Premium data based on publicly available pricing from major UK dealers (March 2026).
CGT rules: HMRC Capital Gains Manual CG78300.
Last updated: March 2026
Founder & Market Researcher
Taro has been actively investing in precious metals and financial markets for over 15 years. Frustrated by the lack of transparent, accurate gold pricing information in the UK, he built London Gold Exchange as a data-driven resource for fellow investors. The site combines real-time market data, verified dealer information from 242+ UK businesses, and insights drawn from years of hands-on experience in the gold market.
- ✓15+ years investing in precious metals & equities
- ✓Built verified database of 242+ UK gold dealers
- ✓Daily market data analysis and price tracking
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ViewDisclaimer: This guide is for informational purposes only and does not constitute financial advice. Gold prices, premiums, and bar specifications may change. Always verify current pricing with dealers. Tax rules are subject to change — consult a qualified tax adviser for personalised CGT advice.
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