Gold bar sizes and weights from 1 g to 250 g
Anyone holding investment gold for the first time is usually surprised by how small it is. A 1-gram bar is smaller than the nail on your little finger, and a full 100 grams fits comfortably in the palm of your hand. In this overview you will find the actual dimensions published by the manufacturers of the bars in our range, from 1 g to 250 g. We also explain why the same weight has a different shape at different brands and how much space a gold reserve takes up at home or in a bank safe deposit box. If you are still choosing a size, read our overview of bar weights from 1 g to 1 Oz or browse our full range of gold bars.
Why gold is so small: a density of 19.32 g/cm³
Gold is one of the heaviest metals you are likely to come across. One cubic centimetre of fine gold weighs 19.32 g, about 2.5 times as much as a piece of iron of the same size. That is why a large amount of value fits into a very small volume.
From the density you can calculate how much space the metal itself takes up, regardless of the shape of the bar. To make it easier to picture, we also give the edge length of the cube into which each amount of gold could be “compressed”:
| Weight | Volume of metal | Equivalent cube edge |
|---|---|---|
| 1 g | 0.052 cm³ | 3.7 mm |
| 5 g | 0.259 cm³ | 6.4 mm |
| 10 g | 0.518 cm³ | 8.0 mm |
| 20 g | 1.035 cm³ | 10.1 mm |
| 1 Oz (31.1 g) | 1.610 cm³ | 11.7 mm |
| 50 g | 2.588 cm³ | 13.7 mm |
| 100 g | 5.176 cm³ | 17.3 mm |
| 250 g | 12.94 cm³ | 23.5 mm |
| 1 kg | 51.76 cm³ | 37.3 mm |
A kilogram of gold is therefore a cube with edges of just under 4 cm, smaller than a Rubik’s Cube. The values apply to fine gold 999.9/1000, from which all the investment bars in our range are made. Why gold is traditionally weighed in troy ounces is explained in the article Why gold is weighed in troy ounces.
Dimensions of Argor-Heraeus bars
The Swiss refinery Argor-Heraeus mints flat, wide bars. The dimensions apply to the current design and also to the Kinebar series with a hologram, which has the same dimensions. Each bar comes in an 85 × 55 mm blister with a credit-card-sized certificate.
| Bar | Length × width × thickness |
|---|---|
| 1 g Argor-Heraeus | 15.0 × 8.7 × 0.5 mm |
| 2 g Argor-Heraeus | 19.0 × 11.4 × 0.6 mm |
| 5 g Argor-Heraeus | 23.0 × 14.0 × 0.9 mm |
| 10 g Argor-Heraeus | 31.5 × 18.5 × 1.0 mm |
| 20 g Argor-Heraeus | 40.4 × 23.3 × 1.2 mm |
| 1 Oz Argor-Heraeus | 40.4 × 23.3 × 1.9 mm |
| 50 g Argor-Heraeus | 49.7 × 28.5 × 2.0 mm |
| 100 g Argor-Heraeus | 49.7 × 28.5 × 3.9 mm |
| 250 g Argor-Heraeus (cast) | 50.0 × 31.0 × 9.0 mm |
An interesting detail: at Argor-Heraeus the 20 g and 1 Oz bars share the same footprint and differ only in thickness. The same is true of the 50 g and 100 g bars. Argor-Heraeus does not make a minted 250 g bar; that weight is available only as a cast bar.
Dimensions of PAMP Fortuna bars
Bars from PAMP featuring Lady Fortuna are slightly smaller and thicker than those from Argor-Heraeus. Each one is sealed in a CertiPAMP card with an integrated certificate and Veriscan protection.
| Bar | Length × width × thickness |
|---|---|
| 1 g PAMP Fortuna | 14.7 × 8.9 × 0.40 mm |
| 2.5 g PAMP Fortuna | 19.0 × 11.5 × 0.60 mm |
| 5 g PAMP Fortuna and 5 g PAMP Rose | 22.1 × 13.1 × 0.90 mm |
| 10 g PAMP Fortuna | 26.5 × 15.8 × 1.25 mm |
| 1/2 Oz PAMP Fortuna | 29.5 × 17.1 × 1.61 mm |
| 20 g PAMP Fortuna | 31.0 × 18.0 × 1.88 mm |
| 1 Oz PAMP Fortuna | 41.0 × 24.0 × 1.73 mm |
| 50 g PAMP Fortuna | 47.0 × 27.0 × 2.06 mm |
| 100 g PAMP Fortuna | 47.0 × 27.0 × 4.12 mm |
| 250 g PAMP Fortuna | 60.0 × 35.0 × 6.94 mm |
You can read more about the whole series and how to choose the right size in the article Which PAMP Fortuna weight to choose.
Münze Österreich, Valcambi, Britannia and Perth Mint
Bars from Münze Österreich are produced for the Austrian Mint by Swiss partners, which is why their dimensions are almost identical to those of Argor-Heraeus. Valcambi, The Royal Mint and The Perth Mint use their own formats.
| Bar | Length × width × thickness |
|---|---|
| 1 g Münze Österreich | 15.0 × 8.7 × 0.5 mm |
| 5 g Münze Österreich | 23.0 × 14.0 × 0.95 mm |
| 10 g Münze Österreich | 31.5 × 18.5 × 1.05 mm |
| 20 g Münze Österreich | 40.4 × 23.3 × 1.30 mm |
| 100 g Münze Österreich | 49.7 × 28.5 × 3.85 mm |
| 1 g Valcambi | 15.00 × 8.50 × 0.55 mm |
| 5 g Valcambi Green Gold | 23.05 × 13.85 × 1.00 mm |
| 10 g Valcambi | 25.30 × 15.20 × 1.60 mm |
| 5 g Britannia | 23.2 × 14.2 mm (thickness not stated by the manufacturer) |
| 10 g Britannia | 25.7 × 15.7 mm (thickness not stated by the manufacturer) |
| 20 g Perth Mint | max. 31.8 × 18.8 × 2.9 mm |
The dimensions are based on figures from the manufacturers and specialist bullion dealers (as of September 2026). For some brands they differ by tenths of a millimetre between design generations: for example, The Royal Mint used to list older 1 g Britannia bars at 14.7 × 8.9 mm and now lists 14.9 × 9.15 mm. The Perth Mint gives maximum dimensions within its manufacturing tolerance.
Why the same weight comes in different sizes
For the same weight the volume of metal is always the same; only the shape differs. The 20 g bar shows this well: at Argor-Heraeus it measures 40.4 × 23.3 × 1.2 mm, at PAMP 31.0 × 18.0 × 1.88 mm. The first is flatter and looks bigger, the second is more compact and thicker. Manufacturers choose the shape according to their minting tools, design and packaging; it makes no difference to the gold content.
The stated thickness is also an “envelope” measurement: it is taken across the minted relief, so the actual amount of metal is slightly less than if you simply multiplied the dimensions. Bars differ even more depending on how they are made. Minted bars are stamped from rolled sheet, have sharp edges and are thin. Cast bars are poured into a mould, tend to be thicker and have sloping sides. The cast 250 g Argor-Heraeus bar is 9 mm thick, the minted 250 g PAMP bar only 6.94 mm.
Large bars for comparison
The cast kilo bar traded by banks and large investors measures about 117 × 52 × 9 mm at Swiss refineries, slightly smaller than a typical smartphone, though thicker and much heavier. The standard bar for the interbank market under the LBMA Good Delivery rules contains 350 to 430 troy ounces (about 11 to 13 kg of gold). The recommended size of the top surface is 250 × 70 mm and the height around 35 mm. Bars like these are held by the central banks we write about in the article Fort Knox: myth and reality.
How much space a gold reserve takes up
The metal itself is tiny. Ten 100 g Argor-Heraeus bars, one kilogram of gold, stacked on top of each other would form a column with a footprint of 49.7 × 28.5 mm and a height of just 39 mm. Most of the space, however, is taken up by the packaging, because every bar has its own blister. At Argor-Heraeus the blister measures 85 × 55 mm, roughly the size of a credit card, whether it holds a 1 g or a 100 g bar.
When planning storage space, it is therefore better to think in number of pieces rather than weight. A hundred 1 g bars take up far more room than one 100 g bar, even though they contain the same amount of gold. Smaller weights, on the other hand, are more practical if you want to sell gradually. How to strike the right balance is discussed in the article Premium on gold: why the price per gram differs.
The blister is part of a bar’s value. Do not open it, do not put stickers on it and store it flat, ideally in a box or a card case. What to do if the packaging does get damaged is described in the article Damaged blister or lost certificate. Storage options at home, in a bank and in professional custody are compared in the article How to store investment gold.
Dimensions and weight as an authenticity check
Because the density of gold is known, checking the dimensions and weight helps to spot a crude fake. A bar with a gold-plated brass or lead core would have to be visibly larger to reach the correct weight. That is not enough for sophisticated fakes, however: tungsten has a density of 19.25 g/cm³, almost the same as gold, and a bar with a tungsten core would pass on both dimensions and weight.
The most reliable protection is to buy new bars in an intact blister from a trusted dealer and, if in doubt, to have them tested with an instrument. What to look out for is summarised in the articles How to verify investment gold and Kinebar and Veriscan security features.
Frequently asked questions
How big is a 1 g gold bar?
About 15 × 9 mm, with a thickness of 0.4 to 0.55 mm depending on the manufacturer. It is smaller than the nail on your little finger and thinner than a bank card. It is still easy to handle, because it is sealed in a blister, which at Argor-Heraeus measures 85 × 55 mm.
How big is a 100 g gold bar?
A minted 100 g bar measures 49.7 × 28.5 × 3.9 mm at Argor-Heraeus and 47 × 27 × 4.12 mm at PAMP Fortuna. Its footprint is roughly that of a small matchbox, but it is only about 4 mm thick.
Why is the 1 Oz Argor-Heraeus bar the same size as the 20 g bar?
The manufacturer uses the same 40.4 × 23.3 mm footprint for both weights and handles the difference in gold content through thickness: the 20 g bar is 1.2 mm thick, the ounce bar 1.9 mm. You can tell the two sizes apart by the weight stamped on the bar and stated on the certificate.
How big is a kilogram of gold?
As pure metal it takes up 51.8 cm³, a cube with edges of just under 4 cm. A typical cast kilo bar is shaped like a flat brick of about 117 × 52 × 9 mm.
Are bar dimensions accurate to a tenth of a millimetre?
Manufacturers work with tolerances, and some dimensions change slightly between design generations. Differences of a few tenths of a millimetre are therefore normal and do not indicate a fake. What matters is the weight, the fineness of 999.9/1000, an intact blister and the certificate.
Will gold fit in a bank safe deposit box?
Yes. The bars themselves are small, so the box size you need depends mainly on the number of blisters and how you store them. Box sizes vary from bank to bank, so check them before you rent one.
About the author
Adolf Baumann, analyst at Baumann Group a.s. (GOLDU), has been working with precious metals for over 30 years. He has seen euphoria, crashes and panic on the markets – and he still enjoys it. He explains in plain language what moves the price of gold and silver and how to handle them without unnecessary mistakes. His weakness? He refuses to wear a suit.
