Discount Calculator
Discount Calculator
The price after a discount and how much you save — including a second discount on top of the first, where 20% plus 10% comes to 28% off, not 30%.
Price after discount
$2,000, 20% off, then a further 10% off
Price after one or two discounts
- P
- the original price
- d1, d2
- the first and second discount, in %. The order does not change the result.
- Before the discount
- original price = sale price ÷ [(1 − d1 ÷ 100) × (1 − d2 ÷ 100)]
Worked example
$2,000, 20% off, then a further 10% off
After 20%: 2,000 × 0.80 = $1,600
After a further 10%: 1,600 × 0.90 = $1,440.00
You save $560, which is 28% of 2,000 — not 30% ($1,400)
Two discounts in a row, as one discount
| Offer | Looks like | Actually |
|---|---|---|
| 10% then 10% | 20% | 19% |
| 20% then 10% | 30% | 28% |
| 30% then 20% | 50% | 44% |
| 40% then 10% | 50% | 46% |
| 50% then 20% | 70% | 60% |
| 50% then 50% | 100% | 75% |
Why 20% + 10% is 28%
A second discount is taken off a price that has already been reduced, so it is a percentage of a smaller number. On a $2,000 item, 20% off leaves $1,600; a further 10% off that is $160, not the $200 that 10% of the original would be. The total saving is $560, or 28% of the original price. Two 50% discounts come to 75% off, not a free item. The order makes no difference: 10% then 20% gives the same price as 20% then 10%.
To go the other way — to find the price before a discount from the sale price — divide rather than add back: $1,440 after 20% and 10% off was 1,440 ÷ (0.80 × 0.90) = $2,000. Adding 28% to $1,440 would give the wrong answer, for the same reason markup and margin differ (see the profit margin calculator).
A few things to check before trusting a “sale” figure. A discount is only as real as the price it starts from, so compare the price you pay with what the same item sells for elsewhere. Cashback that arrives later, or a card offer capped at a maximum amount, is not the same as money off at the till. In India the MRP on packaged goods already includes GST, so a discount on the MRP is a discount on the tax-inclusive price; elsewhere, check whether a shelf price includes VAT (the VAT calculator separates it). If you sell, and want to know what a discount does to your margin, work out the discounted price here and put it into the margin calculator. This is arithmetic on the figures you enter, not financial advice.
Frequently asked questions
How do I calculate a discount?
Multiply the price by (1 − discount ÷ 100). 20% off $2,000 is 2,000 × 0.80 = $1,600.
Is 20% + 10% off the same as 30% off?
No. The second discount applies to the reduced price, so the total is 28%. On $2,000 you pay $1,440, not $1,400.
How do I find the original price from the sale price?
Divide the sale price by (1 − discount ÷ 100). $1,600 after 20% off was 1,600 ÷ 0.80 = $2,000.
Does the order of two discounts matter?
No. Both are multiplications, so 10% then 20% gives the same final price as 20% then 10%.
Related calculators
References
- Legal Metrology (Packaged Commodities) Rules, 2011 (India): the retail sale price declared on a package is the maximum retail price inclusive of all taxes.
- Consumer Protection Act, 2019 (India), section 2(47): false or misleading representations, including about price, are an unfair trade practice.
- Garrison RH, Noreen EW, Brewer PC. Managerial Accounting. McGraw-Hill. Gross margin, contribution margin and cost-plus pricing (markup on cost).