Calculators & everyday math
How to Calculate a Sale Discount and Sale Price
A sale sign gives you a percentage; what you want to know is the price at the register and how much you keep. This guide shows the two-step and one-step methods, how to work backwards from a sale price, and how to find the discount percentage when a shop shows only two prices.
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The two-step method
- Find the savings: price × discount ÷ 100. 30% off $70 saves $70 × 30 ÷ 100 = $21.
- Subtract the savings from the price: $70 − $21 = $49.
The one-step method
Multiply the price by the share you pay instead of the share you save. With 30% off you pay 70%, so $70 × 0.7 = $49. This is quicker when you only care about the final price.
Finding the original price
If a tag shows only the sale price, divide by the share you pay. A $49 item marked “30% off” was $49 ÷ 0.7 = $70 before the sale.
Finding the discount percentage
If you see an old price and a new one, the discount is (old − new) ÷ old × 100. A jacket reduced from $120 to $90 is $30 off, and 30 ÷ 120 × 100 = 25% off.
Rounding to the cent
Savings often come out with fractions of a cent: 15% of $19.99 is $2.9985. Round the savings to the nearest cent ($3.00) and subtract it, so the savings and the sale price add up to the original: $3.00 + $16.99 = $19.99. Stores may round differently, so expect the odd cent of difference at the register.
Calculate a Sale Discount FAQ
- How do I calculate 30% off a price?
- Multiply the price by 0.7. 30% off $70 is $49.
- How do I find the original price from the sale price?
- Divide the sale price by 1 − the discount ÷ 100. $49 after 30% off was $49 ÷ 0.7 = $70.
- How do I find the discount percentage from two prices?
- Subtract the sale price from the original, divide by the original, and multiply by 100. $120 to $90 is 25% off.
- Is the discount taken before or after tax?
- That depends on the store and where you are. The arithmetic is the same either way; the Discount Calculator works on whatever price you enter and does not add tax.
- Does the math change in another currency?
- No. A percentage discount works exactly the same way in any currency.
Related guides
- Savings at Common DiscountsA quick reference of sale prices at 10%, 20%, 25%, and 50% off, mental shortcuts for each, and why a bigger percentage isn’t always the better deal.
- Stacked DiscountsHow stacked percentage discounts combine, a multiplier table for common pairs, when order matters with fixed-amount coupons, and how to compare offers.
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