To work out how much you saved in a sale, subtract what you paid from the full price of every item, then add the savings together. Divide that total by the combined full price to get your overall percentage off. The calculator above does this for a whole basket, so you can see your total saving, what you actually spent and your true discount in one go.
How to calculate your total sale savings
There are three numbers to track:
- Total saved = total of the original prices − total of the prices you paid
- Overall % off = total saved ÷ total of the original prices × 100
- Total spent = the sum of the prices you paid
Work with the basket as a whole rather than averaging each item's percentage. A 50% reduction on a £10 top matters far less than 20% off a £200 coat.
Worked example: a three-item sale basket
| Item | Was | Now | Saved |
|---|---|---|---|
| Coat | £90 | £63 | £27 (30%) |
| Boots | £60 | £45 | £15 (25%) |
| Top | £30 | £24 | £6 (20%) |
| Total | £180 | £132 | £48 (26.7%) |
The overall saving is £48 ÷ £180 = 26.7%. The simple average of 30%, 25% and 20% is 25%, which understates the saving because the coat, your biggest discount, is also your most expensive item.
Include full-price items and codes for a truthful figure
Real baskets are messy. Add the items you bought at full price too, otherwise the headline percentage looks better than your real shopping trip. Here is the same basket with a £50 pair of jeans at full price:
| Step | Original total | You pay | Saved |
|---|---|---|---|
| Sale items plus full-price jeans | £230 | £182 | £48 (20.9%) |
| After a 10% voucher code on the £182 | £230 | £163.80 | £66.20 (28.8%) |
| Adding £3.99 delivery | £230 | £167.79 | £62.21 (27.0%) |
The full-price item pulls the overall discount down from 26.7% to 20.9%. The code lifts it back up, and delivery claws a little back. Check the combined result with the Stacked Discount Calculator, and test whether paying a bit more would unlock free postage with the Free Delivery Calculator.
Note that many retailers exclude sale items from voucher codes, so the 10% above only applies if the terms allow it.
Is a sale saving a real saving?
A saving on paper is not money in your pocket. In the example, you still spent £132 to "save" £48. The saving is only real if it was something you were going to buy anyway.
A more honest check is to compare against your budget, not the label. If you planned to spend £100 on a coat and paid £63 for one, you are £37 better off. If you had no plan to buy boots, the £45 is simply extra spending.
Checking the "was" price
Under UK consumer law, a reference price should be genuine and must not mislead. The Competition and Markets Authority (CMA) lists misleading reference pricing as an unlawful practice, and its published guidance on discounts says the higher price should have been a real price charged for a meaningful period before the sale.
The CMA has not set one universal number of days, so you cannot rely on a "28-day rule". Practical checks are better:
- Compare the same item at two or three other UK retailers.
- Use a price-history tool if the item is available on a marketplace.
- Be wary of "was" prices that never seem to apply, or "up to" claims where few items hit the top discount.
If the original price is doubtful, enter the lowest price you have seen elsewhere in the calculator instead. That gives you a savings figure you can trust.
Making a sale basket go further
- Write a shopping list before the sale starts so discounts do not decide what you buy.
- Check the returns policy. Sale items are often covered as normal, but a charge for returns can wipe out a small saving.
- Look at cost per use or per unit for everyday items. The Price Per Unit Calculator shows whether a multibuy is really cheaper.
- Consider cashback. Where it is offered, it comes off what you paid. See the Cashback Calculator.
- Remember VAT. UK shelf and online prices to consumers normally include it. If you are comparing a trade price, use the VAT Calculator.
- Paying later is not saving. Splitting a sale purchase can help cash flow, but see the Pay in 3 Calculator to check the terms.
How to use the sale savings calculator
- Enter the original (was) price and the sale price you paid for each item.
- Add as many items as you need. Leave the sale price blank for anything you bought at full price.
- Read your total saving, total spend and overall percentage off.
To check a single item quickly, use the Discount Calculator. If you want to see what repeated bargains add up to across twelve months, try the Annual Savings Calculator. For live sales and codes, browse PrimeVoucher's stores.