Gold Bars Explained: Sizes, Brands, and Premiums
Straight answer
Gold bars are the cheapest way to buy a given weight of gold, because their premium over spot drops as the bar gets bigger — a 1-gram bar might cost 15–30% over spot, while a 1-kilo bar can run under 1%. The trade-offs: bars are harder to sell in small pieces, and they take slightly more care to authenticate than well-known sovereign coins. They suit larger stackers who want maximum metal per dollar and plan to hold, not trade in fragments.
A gold bar is a rectangular slab of refined gold stamped with its weight, purity, and the mark of its refiner. Below the surface, though, bars vary a lot — in size, in how they’re made, and in who made them — and those differences decide both what you pay and how easily you can resell. Here’s how to read a bar.
Bar sizes run from 1 gram to 1 kilogram, and bigger means cheaper per ounce
Investment-grade gold bars come in a wide ladder of weights. The common sizes are 1 gram, 5 grams, 10 grams, 1 troy ounce (about 31.1 grams — heavier than the ordinary ounce in your kitchen), 10 troy ounces, and 1 kilogram (about 32.15 troy ounces). A 1-kilo bar at recent prices is a five-figure object; a 1-gram bar is roughly the size of a postage stamp.
The single most important pattern to understand is this: the smaller the bar, the higher the premium you pay over the spot price of gold. Spot is the global market price for a troy ounce of pure gold. Every bar costs spot plus a premium that covers refining, minting, packaging, dealer margin, and the fixed costs of making and handling that piece. Those fixed costs are spread over very little metal in a 1-gram bar, so the percentage markup is steep. Spread the same costs over a kilo and the markup nearly vanishes.
That’s why a serious buyer who wants the most metal per dollar gravitates toward larger bars. We unpack the mechanics of markup in our guide to gold premiums over spot; the short version is that premium is a round-trip cost — you buy above spot and sell below it — so minimizing it matters over time.
| Bar size | Approx. metal content | Typical premium over spot |
|---|---|---|
| 1 gram | 0.032 oz | ~15–30% |
| 5 grams | 0.161 oz | ~8–14% |
| 10 grams | 0.322 oz | ~6–10% |
| 1 troy oz | 1.0 oz | ~3–5% |
| 10 troy oz | 10.0 oz | ~1.5–3% |
| 1 kilogram | 32.15 oz | ~0.5–1.5% |
Treat those numbers as directional. Premiums shift with demand, with the specific refiner, and with whether you’re buying online versus at a coin shop. But the shape holds in every market: the curve falls sharply as size rises.
Minted vs. cast bars: finish versus value
Bars are made two ways, and the difference shows up in both look and price.
Minted (or “struck”) bars
Minted bars start as a strip of refined gold that’s cut to size and stamped under pressure, much like a coin. The result is a precise, polished bar with sharp edges and crisp lettering, usually sealed in a tamper-evident plastic assay card. Most small bars — 1g through about 100g — are minted. They look premium, and they carry a slightly higher markup because of the extra production steps.
Cast (or “poured”) bars
Cast bars are made by pouring molten gold into a mold and letting it cool. They have a rougher, more organic surface and irregular shape — each one is a little different. Casting is cheaper and is the standard method for larger bars, especially 10 oz and 1 kilo. For a big-bar buyer, a cast bar’s lower production cost is a feature, not a flaw: you’re paying for metal, not finish.
Neither method makes the gold inside more or less pure. A cast kilo bar from a top refiner is the same 999.9 fine gold as a glossy minted one. The choice is mostly about whether you value presentation (minted) or rock-bottom premium (cast).
LBMA-accredited refiners are what make a bar liquid
A gold bar is only as trusted as the name stamped on it. The reference standard is the LBMA Good Delivery List — a register maintained by the London Bullion Market Association of refiners whose bars meet strict purity and consistency requirements. A bar from an LBMA-accredited refiner is accepted worldwide with minimal fuss, which directly affects how easily you can sell it later.
The names worth knowing:
- PAMP Suisse — Swiss refiner famous for its “Lady Fortuna” minted bars and tamper-evident assay packaging.
- Valcambi — another major Swiss refiner, known for the CombiBar (more on that below).
- Royal Canadian Mint — government mint, also produces widely traded bars and the Maple Leaf coin.
- Perth Mint — Australian government mint with a strong global reputation for bars and coins.
- Argor-Heraeus — Swiss-German refiner whose bars are a fixture in the wholesale market.
Buying outside this circle isn’t automatically a mistake, but it narrows your resale market and may force you to pay for re-assay when you sell. Sticking to recognized refiners is the simplest way to protect liquidity. For more on vetting metal generally, see authenticating gold.
Assay certificates and serial numbers
Reputable small bars ship sealed in an assay card — a tamper-evident package that certifies the bar’s weight and purity, printed with a unique serial number that matches a number stamped on the bar itself. That matched pair is part of the bar’s identity. Keep the bar in its sealed assay card: breaking the seal can lower resale value, because the next buyer loses the easy assurance the packaging provides.
Security features that help you (and your buyer) trust the bar
Because a bar is a plain slab of high-value metal, refiners have built in anti-counterfeiting features:
- Veriscan (Royal Canadian Mint) — the mint records a microscopic “fingerprint” of each bar’s surface; a dealer can later scan it and confirm the bar matches the mint’s database.
- CertiPAMP (PAMP Suisse) — a tamper-evident assay holder with a unique serial number and security features that make tampering obvious.
- Valcambi CombiBar — a credit-card-sized sheet scored into small, breakable segments (for example, fifty 1-gram squares). It’s a clever answer to the “hard to sell in part” problem, letting you snap off small amounts to sell or gift — though you pay a higher per-gram premium for that flexibility.
None of these replace buying from a trusted dealer, but they raise the bar (so to speak) for counterfeiters and give your eventual buyer confidence.
The honest trade-off: cheapest weight, but less flexible than coins
Bars win on cost and lose on flexibility. Here’s the full picture.
What bars do well: they deliver the most gold per dollar. If your goal is to accumulate weight and hold it, a few large bars beat a pile of coins on premium, often by several percentage points — money that stays in your pocket.
Where bars fall short: a 1-kilo bar is an all-or-nothing asset. You can’t sell a third of it; you sell the whole thing or none of it. Sovereign coins like the American Eagle or Canadian Maple Leaf are sold one at a time, so they let you raise smaller amounts of cash and are instantly recognized by almost any dealer. Coins are also marginally easier to authenticate, because their exact specifications are public and widely known. We compare these formats head-to-head in forms of physical gold.
So the choice tracks your purpose. Bars are the efficient way to store wealth in gold; coins are the flexible way to spend or sell it incrementally.
- You expect to sell gradually — coins let you liquidate in small amounts; a big bar doesn’t.
- You’re spending only a few hundred dollars — small bars carry the worst premiums of any common gold format.
- You can’t store a high-value item securely and insured.
- You’d buy from a marketplace like Amazon or eBay, where counterfeit bars circulate. Use established dealers instead.
Who gold bars suit
Bars are built for the larger stacker — someone past the beginner stage who is committing real money to physical gold and treating it as a long-term holding. If you’re buying ten ounces or more, the premium savings on larger bars are substantial. If you’re easing in with a few hundred dollars at a time, you’re usually better served by fractional coins or rounds, even though the per-unit premium is higher, because liquidity and authentication are simpler. Where you actually buy matters as much as what you buy — see where to buy gold for vetting dealers.
Why are small gold bars so much more expensive per ounce?
The fixed costs of refining, minting, packaging, and handling are nearly the same whether a bar holds 1 gram or 1 kilogram. Spread over a tiny bar, those costs become a large percentage markup; spread over a kilo, they’re negligible. That’s why a 1-gram bar can cost 15–30% over spot while a kilo bar runs under 1.5%.
Are cast bars worth less than minted bars?
Not in metal terms. A cast bar and a minted bar from the same refiner contain identical pure gold. Minted bars cost a bit more because of extra production steps and polished presentation. For maximizing weight per dollar, a cast bar from a recognized refiner is often the better value.
Should I keep a bar in its sealed assay card?
Yes. The tamper-evident assay card certifies weight and purity and carries a serial number matching the bar. Keeping the seal intact makes resale easier and protects value — breaking it forces the next buyer to re-verify the bar themselves.
Are gold bars harder to sell than coins?
Larger bars are harder to sell in part, since you can’t divide one — it’s all or nothing. Sovereign coins sell one at a time and are instantly recognized everywhere, making them more flexible for raising small amounts. Bars from LBMA-accredited refiners still sell easily as whole units.