Banks and the Post Office weigh coin bags rather than counting them. Standard bag values: 1p and 2p £1, 5p and 10p £5, 20p and 50p £10, £1 and £2 £20.
How to use the UK Coin Weight Calculator
- Coin
- Weight of the coins
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose the coin, enter the weight (without the bag) and see the count and value.
Tips
- Rates and thresholds follow the UK tax year, 6 April to 5 April.
- Scotland has its own income tax bands for non-savings income.
- Check your tax code on your payslip – it changes your personal allowance.
- Use HMRC’s own tools for a final figure.
Common mistakes to avoid
- Using last year’s thresholds.
- Forgetting student loan and pension deductions.
- Confusing National Insurance with income tax.
Inputs explained
| Field | What to enter |
|---|---|
| Coin | Choose one: 1p, 2p, 5p, 10p … |
| Weight of the coins | In g |
What each result means
- Number of coins = round([Weight of the coins]÷[Weight of one coin])
- Value = [Number of coins]×[Face value]
- Weight of a full standard bag = [Standard bag value]÷[Face value]×[Weight of one coin]
Example values
How the main result changes when Weight of the coins changes and everything else stays at the example values above:
| Weight of the coins (g) | Value |
|---|---|
| 80 | 5 |
| 120 | 7.5 |
| 160 | 10 |
| 200 | 12.5 |
| 240 | 15 |
| 320 | 20 |
Formula
Number of coins = total weight ÷ weight of one coinValue = number of coins × face valueCoin weights: 1p 3.56 g, 2p 7.12 g, 5p 3.25 g, 10p 6.5 g, 20p 5 g, 50p 8 g, £1 8.75 g, £2 12 gWorked example
Inputs — Coin: 50p; Weight of the coins: 160 g.
Results — Weight of one coin = 8 g; Number of coins = 20; Value = £10.00; Standard bag value = £10.00; Weight of a full standard bag = 160 g.
Frequently asked questions
How much does a £1 coin weigh?
8.75 grams (the 12-sided coin).
How much does a bag of 20p coins weigh?
A £10 bag of 50 coins weighs 250 g.
Why do banks weigh coins?
It's faster than counting and accurate for standard coins.
What formula does the UK Coin Weight Calculator use?
Number of coins = total weight ÷ weight of one coin.