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FREE CALCULATOR

Discount Calculator

Free discount calculator: find the sale price, the percent off, the original price before a discount, or stack two discounts. Instant results, no sign-up.

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🏷️Discount Calculator

How to Use the Discount Calculator

This discount calculator answers the four questions people actually ask when shopping or pricing: what will I pay, how much is it really off, what did it cost before the sale, and what happens when two discounts stack. Pick a tab, type your numbers, and the result updates as you type. It works in any currency — the figures are just numbers.

Sale price: Enter the original price and the discount percentage. You get the sale price and the amount saved. Add a sales tax rate if you want the final price at the till.

Percent off: Enter the original price and the sale price to find out how big the discount really is. Useful when a tag shows two prices but no percentage.

Original price: Enter what you paid and the discount you were given to work out the price before the sale.

Two discounts: Enter a price and two percentages to see the final price after both — and the true combined discount.

Discount Formulas

Common Discounts on a 100 Price

DiscountSale priceYou saveMultiplier
5% off95.005.00× 0.95
10% off90.0010.00× 0.90
15% off85.0015.00× 0.85
20% off80.0020.00× 0.80
25% off75.0025.00× 0.75
30% off70.0030.00× 0.70
40% off60.0040.00× 0.60
50% off50.0050.00× 0.50
60% off40.0060.00× 0.40
70% off30.0070.00× 0.30

For any other price, multiply it by the multiplier: 30% off 249.90 is 249.90 × 0.70 = 174.93.

Frequently Asked Questions

How do I calculate a discount?+
Multiply the original price by the discount rate as a decimal, then subtract the result. Example: 20% off 80 is 80 × 0.20 = 16, so the sale price is 80 − 16 = 64. Shortcut: multiply the price by (1 − 0.20) = 0.80 to get the sale price in one step.
How do I find the percent off from two prices?+
Percent off = (Original − Sale) ÷ Original × 100. Example: an item that cost 60 and is now 45 is (60 − 45) ÷ 60 = 0.25, so 25% off.
How do I find the original price before a discount?+
Original = Sale price ÷ (1 − discount rate). Example: 72 after 20% off was 72 ÷ 0.80 = 90. Do not add 20% to 72 — that gives 86.40, which is wrong because the discount was taken from the bigger number.
Is 20% off plus 10% off the same as 30% off?+
No. The second discount applies to the already reduced price. 100 − 20% = 80, then 80 − 10% = 72, a total of 28% off, not 30%. In general, the combined multiplier is (1 − d1) × (1 − d2).
Is sales tax charged before or after the discount?+
Usually on the discounted price, because that is what you actually pay. Rules vary by country, state and coupon type (some manufacturer coupons do not reduce the taxable amount), so check your receipt or local rules.
How can I work out a discount in my head?+
10% off: move the decimal one place and subtract. 20% off: take 10% twice. 25% off: subtract a quarter. 50% off: halve it. For 15%, take 10% and add half of that. Example: 15% off 80 = 8 + 4 = 12 saved, so 68.

All Calculators

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How Discounts Really Work

A discount is a percentage of the original price taken off, so the number you pay is always the original multiplied by what is left. A 25% discount leaves 75% of the price, which is why multiplying by 0.75 gives the sale price in a single step. That one idea explains every calculation on this page.

Worked example

A jacket costs 120 and is marked 35% off. It leaves 65% of the price: 120 × 0.65 = 78. You save 42. If the shop then adds 8% sales tax to the sale price, you pay 78 × 1.08 = 84.24.

Why two discounts never add up

“Take an extra 10% off” applies to the price that is already reduced. 20% then 10% is 0.80 × 0.90 = 0.72 — you pay 72% of the original, a 28% discount. The more you stack, the larger the gap between the sum of the percentages and the real saving, so a 50% and a 50% discount together give 75% off, not 100%.

Working backwards from a sale price

To recover the original price, divide by what was left; do not add the discount back. A coat that cost 60 after 25% off was 60 ÷ 0.75 = 80. Adding 25% to 60 gives 75, which is the usual mistake.

A discount and its reverse are not equal

Prices that fall by 20% must rise by 25% to get back to where they started: 100 → 80, then 80 × 1.25 = 100. This asymmetry is why “was 100, now 80” and “save 25% by paying 80 instead of 100 next time” describe the same gap from two different starting points.

Comparing offers

The biggest percentage is not always the biggest saving. 50% off a 20 item saves 10; 15% off a 200 item saves 30. When two deals compare different prices, look at the final price you pay, not just the percentage on the tag.