Calculators

Discount Calculator

The sale price and how much you save, including an extra coupon on top and any tax added at the till.

How it works

Each discount comes off the price that is left after the one before it, so stacked discounts multiply rather than add. 20% off and then an extra 10% leaves 0.8 × 0.9 = 72% of the price, a 28% discount rather than 30%. Tax, when a shop adds it at the till, is charged on the discounted price.

price × (1 − d₁) × (1 − d₂)
d₁
The main discount, as a decimal
d₂
An extra coupon or bank offer applied after it
Total discount
1 − (1 − d₁)(1 − d₂)

Worked example

A ₹2,000 jacket at 20% off, with an extra 10% off at checkout.

  1. 1After 20% off: 2,000 × 0.8 = ₹1,600
  2. 2After the extra 10%: 1,600 × 0.9 = ₹1,440
  3. 3Saving: 2,000 − 1,440 = ₹560
  4. 4Total discount: 560 ÷ 2,000 = 28%

You pay ₹1,440 and save ₹560, a 28% discount rather than the 30% the two numbers suggest.

Frequently asked questions

Is 20% off plus 10% off the same as 30% off?

No, it is 28%. The second discount applies to the already reduced price, so it takes 10% of a smaller number. The gap grows with bigger discounts: 50% plus 50% is 75% off, not free.

How do I work out a discount in my head?

Find 10% by moving the decimal point one place, then scale. 10% of ₹2,000 is ₹200, so 20% is ₹400 and 25% is ₹500. For 30% off, take 3 × 10%.

How do I find the original price from a sale price?

Divide by what is left after the discount. A ₹1,200 price after 25% off was 1,200 ÷ 0.75 = ₹1,600. The percentage calculator can also do this in reverse.

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