How the discount is calculated
The calculator multiplies the price by what is left after the discount: price × (1 − discount ÷ 100). With a second discount it repeats the step on the new price: price × (1 − d1 ÷ 100) × (1 − d2 ÷ 100). The result also shows your combined saving as a single percentage.
Why two discounts are worth less than their sum
Shops often advertise "50% off plus extra 20% off". That is not 70%. The extra 20% is taken from the half-price, so you actually save 60%. Always compare the final price you pay, not the headline percentages.
Smart shopping tips
- Check whether the old price was real. A "70% off" tag on an inflated price is not a bargain.
- Bank card and voucher offers are usually applied after the sale price, which is exactly what the extra discount box models.
- Remember delivery fees and sales tax. Use the sales tax calculator if tax is added, or the percentage calculator for other questions.
Frequently asked questions
How do I calculate a discount?
Sale price = original price × (1 − discount ÷ 100). A 10,000 item at 30% off costs 10,000 × 0.70 = 7,000, so you save 3,000.
Is 20% off plus 10% off the same as 30% off?
No. The second discount applies to the already reduced price. On 10,000, 20% off gives 8,000 and a further 10% off gives 7,200. The total saving is 28%, not 30%.
Does the order of two discounts matter?
No. Two percentage discounts give the same final price in either order, because the multiplication is the same: 0.80 × 0.90 = 0.90 × 0.80.
How do I work out the original price from the sale price?
Divide the sale price by (1 − discount ÷ 100). If you paid 7,000 after 30% off, the original price was 7,000 ÷ 0.70 = 10,000.
Does this include sales tax or delivery?
No. It only calculates the discount. If tax is added at the till, use the sales tax calculator on the final price.