The current UK coins used in everyday change weigh from 3.25g for a 5p to 12g for a £2. The table below gives the Royal Mint specifications for the eight circulating denominations.
| Denomination | Weight (g) | Diameter (mm) | Thickness (mm) |
|---|---|---|---|
| 1p | 3.56 | 20.3 | 1.65 |
| 2p | 7.12 | 25.9 | 2.03 |
| 5p | 3.25 | 18.0 | 1.70 |
| 10p | 6.50 | 24.5 | 1.85 |
| 20p | 5.00 | 21.4 | 1.70 |
| 50p | 8.00 | 27.3 | 1.78 |
| £1 | 8.75 | 23.43 | 2.80 |
| £2 | 12.00 | 28.4 | 2.50 |
These are the specifications for the current denominations. A worn, dirty or damaged coin can give a different reading on a household scale. Older coins may also be a different size, weight or composition, so compare the date and design before using the table to identify one.
Which UK coin is the heaviest?
The £2 coin is the heaviest coin in current UK circulation at 12g. The 50p is next at 8g. A cupro-nickel £5 crown weighs 28.28g, but it is a commemorative coin rather than an everyday circulating denomination.
Weights of older UK coins
Some familiar denominations have changed over time. The current 5p and 10p are smaller versions introduced in 1990 and 1992. The larger earlier versions were withdrawn from circulation. The current 50p was introduced in 1997; the earlier, larger 50p was demonetised in 1998.
The round £1 coin was replaced by the 12-sided £1 in 2017. A former round £1 weighs 9.50g, while the current 12-sided £1 weighs 8.75g. For a date-specific identification, use the coin’s design as well as its measurement.
For more background, see our guides to when the 5p changed and the first decimal coins.
Can you count UK coins by weight?
You can make a rough count only when the coins are the same current denomination and the scale is accurate enough. Divide the total weight by the table figure, then multiply the result by the coin’s face value.
For example, 336g of current 50p coins is 42 coins at 8g each. Their face value is £21. This method is not reliable for mixed coins, older versions, counterfeit coins or a scale with a coarse reading.
How much do 100 pennies weigh?
One hundred current 1p coins weigh 356g using the Royal Mint’s 3.56g specification. The result is a reference figure rather than proof that every coin is identical.
Royal Mint specifications
The figures above are based on the Royal Mint’s coin designs and specifications pages. The Mint provides separate pages for each denomination, including former versions and changes in composition.
How to assess a coin’s value
A coin’s value depends on what it is, its condition and the evidence available for comparable sales. A listing price is an asking price, not proof of what a buyer paid. When comparing examples, record the date, condition, design or variant and whether the sale was completed.
Use official specifications to check the denomination, design and physical details before comparing prices. The Royal Mint publishes coin designs and specifications, as well as UK circulating-coin mintage figures. Mintage can help describe a coin’s production history, but it does not set a sale price.