Original price after 50% off
Enter what you paid and this page works back to the pre-sale price. The discount is fixed at 50% — the price is yours to change.
Worked example at 50% off
You paid £37.50 in a 50% off sale.
- 100% − 50% = 50% of the original price remains
- As a decimal that is 0.5
- 37.5 ÷ 0.5 = £75.00
- You saved £37.50
Check it forwards: £75.00 − 50% = £37.50 ✓
Adding 50% back to £37.50 would give £56.25 — which is wrong, and wrong by more as the percentage grows. The discount was taken off the larger original, so putting it back on the smaller sale price never reaches it.
Where 50% off shows up
Half price is the most psychologically powerful discount in retail, and the easiest to reverse: the original is simply double what you paid. That simplicity is part of why it is advertised so heavily.
It is also the depth where stacked offers get misread most often. "50% off, then a further 50% off" is not free — it is 75% off, because the second half comes off the already-halved price.
50% off price table
What twenty common sale prices were before the 50% reduction. Every figure is divided by 0.5.
| You paid | Original price | You saved |
|---|---|---|
| £6.00 | £12.00 | £6.00 |
| £10.00 | £20.00 | £10.00 |
| £14.00 | £28.00 | £14.00 |
| £18.00 | £36.00 | £18.00 |
| £22.00 | £44.00 | £22.00 |
| £26.00 | £52.00 | £26.00 |
| £30.00 | £60.00 | £30.00 |
| £34.00 | £68.00 | £34.00 |
| £38.00 | £76.00 | £38.00 |
| £42.00 | £84.00 | £42.00 |
| £46.00 | £92.00 | £46.00 |
| £50.00 | £100.00 | £50.00 |
| £54.00 | £108.00 | £54.00 |
| £58.00 | £116.00 | £58.00 |
| £62.00 | £124.00 | £62.00 |
| £66.00 | £132.00 | £66.00 |
| £70.00 | £140.00 | £70.00 |
| £74.00 | £148.00 | £74.00 |
| £78.00 | £156.00 | £78.00 |
| £82.00 | £164.00 | £82.00 |
Doing it without a calculator
Double it. You paid half, so the original is exactly twice the sale price, with no rounding and no division. It is the only depth where the reversal is genuinely instant, which is part of why half price is advertised so relentlessly.
The exact method is always the same: divide by 0.5. 50% off leaves 50% of the original, so dividing by 0.5 undoes it precisely. Multiplying, or adding the percentage back on, gives a number that is always too small — and the error grows with the discount.
Frequently asked questions
›Is 50% off then 50% off the same as 100% off?
No. The multipliers are 0.5 × 0.5 = 0.25, so you pay a quarter of the original — a 75% total discount. Reversing means dividing by 0.25, or multiplying by four.