How to Calculate Discount Percentage (With Examples)
Short answer
Discount % = (original price − sale price) ÷ original price × 100. A jacket cut from $80 to $60 is (80 − 60) ÷ 80 × 100 = 25% off. To get a sale price from a percentage, multiply the original price by (1 − discount ÷ 100): $120 at 25% off is 120 × 0.75 = $90.
Sale season is here, from Thanksgiving deals in Canada and the US to Diwali offers in India. A quick percentage check tells you whether a "big sale" really is big. Here is the simple maths, plus a free discount calculator that does it for you.
Formula 1: find the discount percentage
You know the original price and the sale price, and you want the percentage.
- Subtract: original price − sale price = the amount you save.
- Divide the saving by the original price.
- Multiply by 100.
Example: a pair of shoes goes from ₹1,499 to ₹999. The saving is ₹500, and 500 ÷ 1,499 = 0.3336, so the discount is about 33.4%. Shops often round this to "33% off". Always divide by the original price, not the sale price; dividing by 999 would wrongly give 50%. Our percentage calculator has a "what percent of" mode that does this step.
Formula 2: find the sale price from a percentage
Multiply the original price by what is left after the discount. 25% off leaves 75%, so multiply by 0.75.
| Original price | Discount | Multiply by | Sale price | You save |
|---|---|---|---|---|
| $120 | 25% | 0.75 | $90 | $30 |
| $50 | 40% | 0.60 | $30 | $20 |
| ₹2,000 | 15% | 0.85 | ₹1,700 | ₹300 |
Two discounts do not add up
"25% off, plus an extra 10% at checkout" is not 35% off. The second discount applies to the already reduced price: $120 × 0.75 = $90, then $90 × 0.90 = $81. You saved $39, which is 32.5% of $120. Put 120, 25 and 10 into the discount calculator and it shows the same $81. We explain more everyday cases in percentages in everyday life.
Don't forget sales tax
In Canada and the US, tax is usually added at the till, after the discount. A $90 sale item with 13% HST costs $90 × 1.13 = $101.70. The sales tax calculator and our guide on how to calculate sales tax cover this. In India, GST is normally already included in the printed MRP.
Is it a real deal?
A percentage is only as honest as the "original" price it starts from. In the US, the FTC's Guides Against Deceptive Pricing say a former-price comparison should use a price the item was genuinely offered at. Compare the sale price with what other shops charge, not only with the crossed-out price. If prices went up first, see how to calculate a percentage increase. Sellers thinking about their side of a sale can read profit margin vs markup.
Frequently asked questions
How do I calculate 20% off a price?
Multiply the price by 0.80. For example, 20% off $45 is 45 × 0.80 = $36, a saving of $9.
How do I find the discount percentage from two prices?
Subtract the sale price from the original price, divide by the original price and multiply by 100. $80 down to $60 is 20 ÷ 80 × 100 = 25%.
Is 50% off plus 20% off the same as 70% off?
No. It is 60% off in total: 100 × 0.50 = 50, then 50 × 0.80 = 40, so you pay 40% of the original price.
Is tax charged before or after the discount?
In most Canadian provinces and US states sales tax is charged on the discounted price. Rules vary for coupons and rebates, so check your local tax authority if it matters.