Finance & Money
Free Discount Calculator
Find the sale price, the amount saved, or the discount percentage behind a price cut.
Free to useNo sign-up requiredNo watermarkRuns in your browser
Last reviewed: 30 September 2026 by Vishal Senthilkumar
This free discount calculator turns an original price and a discount percentage into the final sale price and the amount you save. It also runs in reverse: give it the original and the sale price and it tells you what percentage the discount actually is.
That reverse mode is the useful one when shopping. Retailers advertise the headline percentage, but a "was 89.99, now 64.99" sticker does not tell you it is 27.8% off until you work it out.
How this tool works
Enter the original price
The pre-discount price, before any voucher or sale reduction. Decimals are fine.
Enter the discount percentage
Type it, or use the quick-pick buttons for the common values - 10%, 20%, 25%, 50% and so on.
Read the sale price and your saving
You get the final price to pay and the cash amount saved, so you can judge whether the deal is worth it in real money rather than in percentage terms.
How it works
A discount is a percentage taken off the original price. Convert the percentage to a decimal, multiply by the original price to get the saving, then subtract that saving to get the sale price.
You can get to the same answer in one step by multiplying by what remains. 30% off means you pay 70%, so multiplying the original price by 0.7 gives the sale price directly. That shortcut is worth knowing for mental arithmetic in a shop.
To find a discount percentage from two prices, divide the saving by the original price and multiply by 100. Dividing by the sale price instead is the single most common mistake, and it overstates the discount every time.
Stacked discounts multiply rather than add. Two successive 20% reductions do not make 40% off - each one applies to the price after the previous one, giving 36% off in total.
Working out a discount in your head
A few shortcuts make most shop-floor maths quick enough to do without a phone.
- 10% off: move the decimal point one place left. 10% of 48.00 is 4.80.
- 20% off: take 10% and double it. 20% of 48.00 is 9.60, so you pay 38.40.
- 25% off: quarter the price. A quarter of 48 is 12, so you pay 36.
- 50% off: halve it.
- 15% off: 10% plus half of that 10%. For 48: 4.80 plus 2.40 is 7.20.
- 5% off: 10% halved.
Reading sale prices critically
- A percentage means nothing without the base price. 70% off an inflated "was" price can be worse value than 20% off a fair one.
- Two 20% discounts applied one after the other give 36% off, not 40%. The second is calculated on the already-reduced price.
- A "buy one get one free" offer is a 50% discount only if you actually wanted two.
- "Up to 60% off" usually describes a handful of items. The typical reduction is well below the headline.
- Check whether tax is applied before or after the discount, because the order changes the final figure.
Formula
Saving
saving = original price × (discount % ÷ 100)
Sale price
sale price = original price − saving
Sale price in one step
sale price = original price × (1 − discount % ÷ 100)
Discount percentage from two prices
discount % = ((original − sale) ÷ original) × 100
Divide by the original price, never by the sale price.
Two stacked discounts
final = original × (1 − d₁ ÷ 100) × (1 − d₂ ÷ 100)
Worked examples
25% off 80
The saving is 20, so the sale price is 60.
Was 89.99, now 64.99
The saving is 25.00. Divided by 89.99 that is 27.8% off - well short of the "30% off" the sticker might suggest.
Two 20% discounts
100 becomes 80 after the first, then 64 after the second. That is 36% off in total, not 40%.
A voucher on top of a sale
A 15% code on an item already reduced from 200 to 150 takes it to 127.50, a total saving of 36.25% on the original.
Frequently asked questions
Is this discount calculator free?
Yes. It is free to use with no sign-up and no limit on how many prices you check.
How do I calculate the sale price after a discount?
Multiply the original price by one minus the discount as a decimal. For 30% off: original × 0.7. Or enter both figures above and read the answer.
How do I find the discount percentage from two prices?
Subtract the sale price from the original to get the saving, divide that by the original price, then multiply by 100. Dividing by the sale price is a common error that overstates the discount.
Do two 20% discounts add up to 40% off?
No. They give 36% off, because the second discount applies to the already-reduced price. Stacked discounts multiply rather than add.
Should tax be applied before or after the discount?
It depends on the jurisdiction and the retailer. Most consumer prices are advertised with tax already included, so the discount comes off the tax-inclusive figure - but check, because the order changes the total.