UK Coin Weight Calculator
Loose coins are awkward because value and weight do not rise together. A handful of £2 coins can be worth more and weigh less than a jar full of copper. The UK Coin Weight Calculator totals the mass of current UK 1p, 2p, 5p, 10p, 20p, 50p, £1, and £2 coins from the counts you enter. It also shows the total face value and the total number of coins, so you can plan cash bags, postage, storage, charity collections, or a trip to the bank without guessing.
The calculator follows the exact weights encoded in the calculator. It is not a coin authentication tool and it is not designed for old or unusual coins. Older withdrawn designs, commemorative coins, foreign coins, fakes, badly worn coins, and damaged coins may differ from the assumptions here. If you need a money conversion rather than a physical-weight estimate, use the pence to pounds converter. If you are adding the cash total to a household plan, use the budget calculator. For VAT-inclusive purchases made with the cash, the VAT calculator can help.
How to use this calculator
Enter the count for each denomination. Use zero for any coin type you do not have. The result updates from the same set of counts in four ways: combined coin weight in grams, weight in kilograms, face value in pounds sterling, and number of coins. A separate breakdown lists the gram weight contributed by each denomination with a nonzero count.
Counts should be whole coins. The calculator accepts numbers, but a half coin or decimal count is not meaningful for real cash. If you are weighing a sealed bag, check the denomination on the bag before entering the count. If you are counting mixed change, sort first or enter a careful estimate by coin type.
Coin weights used by the calculator
The component stores a value and a weight for each coin:
| Denomination | Face value | Weight per coin |
|---|---|---|
| 1p | £0.01 | 3.56 g |
| 2p | £0.02 | 7.12 g |
| 5p | £0.05 | 3.25 g |
| 10p | £0.10 | 6.5 g |
| 20p | £0.20 | 5 g |
| 50p | £0.50 | 8 g |
| £1 | £1.00 | 8.75 g |
| £2 | £2.00 | 12 g |
The total weight is the sum of each count multiplied by its coin weight:
The kilogram result is the gram total divided by 1,000:
The face value is calculated in parallel:
Those formulas are simple, but the denomination weights vary enough that mental estimates can be poor. For example, 100 one-penny coins weigh 356 g and are worth only £1. Ten £2 coins weigh 120 g and are worth £20.
Checking the primary result
Use the default counts in the calculator: 100 1p coins, 50 2p coins, 40 5p coins, 20 10p coins, 10 20p coins, 4 50p coins, 10 £1 coins, and 5 £2 coins.
The weight calculation is:
| Denomination | Count | Calculation | Weight |
|---|---|---|---|
| 1p | 100 | 100 x 3.56 g | 356 g |
| 2p | 50 | 50 x 7.12 g | 356 g |
| 5p | 40 | 40 x 3.25 g | 130 g |
| 10p | 20 | 20 x 6.5 g | 130 g |
| 20p | 10 | 10 x 5 g | 50 g |
| 50p | 4 | 4 x 8 g | 32 g |
| £1 | 10 | 10 x 8.75 g | 87.5 g |
| £2 | 5 | 5 x 12 g | 60 g |
The combined coin weight is 1,201.5 g, which the kilogram line shows as 1.202 kg when rounded to three decimal places. The face value is £1 + £1 + £2 + £2 + £2 + £2 + £10 + £10 = £30.00. The number of coins is 100 + 50 + 40 + 20 + 10 + 4 + 10 + 5 = 239.
Weight is not the same as value
The calculator is useful because UK coin denominations have very different value-to-weight ratios. Copper 1p and 2p coins are heavy for their value. A bag of 2p coins can be noticeably heavier than a smaller number of higher-value coins. By contrast, £1 and £2 coins carry much more value per gram, even though each individual coin feels substantial.
That difference matters when carrying cash. A charity box full of low-value coins may be heavier than expected, and postage for coins can become uneconomic if packaging is added. Banks and businesses often sort coins by denomination because mixed coin weights do not reveal a reliable value without knowing the counts.
Practical checks
If you plan to post coins, add the envelope, padding, and container weight to the coin-only total. If you are preparing a bank deposit, check the bank’s bag limits and denomination rules rather than relying only on the calculator. If a weighed batch is far from the calculator’s estimate, recheck the count, look for foreign coins, and confirm that the coins are current designs.
For accounting, the face value output is often more useful than the weight. For logistics, the gram and kilogram outputs matter more. Keeping both visible helps spot mistakes: a result with thousands of coins but only a few pounds of value probably means many low-denomination coins, while a high value with modest weight probably means mostly £1 and £2 coins.
Common mistakes
- Mixing current coins with withdrawn round £1 coins or older designs.
- Forgetting to add container or packaging weight for postage.
- Entering the cash value instead of the number of coins in a denomination field.
- Assuming all coins weigh about the same because they are similar in size.
- Rounding each denomination too early instead of summing grams first.
Sources
- UK legislation, Coinage Act 1971, Schedule 1 — statutory coin specifications including weights.
- GOV.UK, Chancellor launches one year countdown to new £1 coin — government announcement noting the 12-sided £1 coin specification.
- GOV.UK, Royal Mint Trading Fund annual report and accounts 2023 to 2024 — official government publication for the Royal Mint’s public reporting.