How to Calculate Discount and Final Sale Price

"30% off" sounds great, but how much do you actually pay — and save? Working out a discount is a simple skill that saves you money and stops you being fooled by a sale that isn't as good as it looks. Here's how to do it in your head, on paper, or instantly with a tool.

The two numbers you want

Every discount has two outputs: the amount you save and the final price you pay. They're two sides of the same calculation, and once you have one, the other is just a subtraction.

Step 1: Calculate the saving

Multiply the original price by the discount percentage (as a decimal). For a $80 item at 30% off:

80 × 0.30 = $24 saved

Step 2: Calculate the final price

Subtract the saving from the original price:

80 − 24 = $56 final price

The one-step shortcut

Here's a trick that's faster once it clicks. If something is 30% off, you pay 70% of the price. So multiply directly by the remaining percentage:

80 × 0.70 = $56

One multiplication, straight to the final price. For 25% off, multiply by 0.75; for 40% off, multiply by 0.60, and so on. (If you need a refresher on the percentage maths itself, see our guide to calculating percentages.)

Watch out for "stacked" discounts

"Extra 20% off already-reduced prices" does not mean 50% off when the first cut was 30%. The second discount applies to the already-lower price: $80 → $56 (30% off) → $44.80 (a further 20% off). Stacked discounts are always smaller than they sound — a common retail trick worth knowing.

Let the tool handle it

When you're standing in a shop or comparing deals, our free discount calculator gives you the saving and final price instantly. Add sales tax afterwards and you'll know the true checkout total.

Bottom line

To find a sale price, either subtract the saving from the original, or — faster — multiply by the percentage you still pay. Keep an eye on stacked discounts, which never add up to as much as they imply, and you'll always know exactly what a deal is really worth.