Discount Calculator

This discount calculator shows the final price after a percentage off, plus the exact savings. A discount calculator turns "20% off" into the number that matters: what you actually pay and what you actually save. Enter the original price and the percentage off, optionally add sales tax, and the final figure appears instantly.

The maths

savings = price × discount% ÷ 100
after discount = price − savings
tax = after discount × tax% ÷ 100
final = after discount + tax

Tax is applied to the discounted price, so the order matters.

Stacking discounts

Apply each discount to the running price one at a time. Percentages do not add: 20% then 10% is a 28% saving, not 30%, because the second discount applies to an already-reduced price.

Worked example

A 120.00 jacket, 25% off, with 8% sales tax:

savings        = 120.00 × 25 ÷ 100 = 30.00
after discount = 120.00 − 30.00 = 90.00
tax            = 90.00 × 8 ÷ 100 = 7.20
final          = 90.00 + 7.20 = 97.20

You save 30.00 and pay 97.20. Notice that the tax is 7.20 rather than the 9.60 it would be on the full price — the discount reduces the tax as well, which is how registers in most jurisdictions compute it and why the order of the two operations is not a detail you can skip.

Comparing two deals

Percentage off is not the same as value. A 40% discount on a 60.00 item saves 24.00; a 15% discount on a 180.00 item saves 27.00. The smaller percentage is the bigger saving because the base price differs, which is exactly why promotional signage leads with the highest percentage rather than the largest reduction.

The second trap is unit price. A 20% discount takes a 500 g pack at 4.00 down to 3.20, or 6.40 per kilogram. A full-price 750 g pack at 5.40 works out at 7.20 per kilogram — so the discounted smaller pack is genuinely cheaper per unit, but only just, and only because you checked. Run both through here and compare the final figures rather than the percentages on the shelf edge.

Stacking, and the order it happens in

Retailers apply discounts to the running price one at a time. A 25% discount followed by a 10% coupon takes 120.00 to 90.00 and then to 81.00 — a 32.5% total saving, not the 35% the two numbers suggest. The missing 2.5% is the tenth that never applied to the quarter already removed.

A few stores apply the coupon to the pre-discount price instead, which is more generous and considerably rarer. If your receipt disagrees with this calculator, that ordering is the likely reason, and the difference is worth understanding before you plan a purchase around it. Sales Tax Calculator separates the tax portion back out again, and Percentage Calculator expresses any saving as a share of the original price.

Private and precise

Every figure is worked out in your browser with standard financial formulas. Nothing you type is uploaded, stored or sent anywhere.