Discount Calculator

See the final sale price and exactly how much you save.

How the calculator works

A simple discount multiplies the original price by the discount percentage and subtracts the result: 25% off an $80 item removes $20, leaving $60. Stacked discounts apply in sequence rather than together — the second percentage acts on the already-reduced price, so “30% + 10%” is not 40% but 1 − 0.70 × 0.90 = 37%. The calculator displays this effective figure so you can compare a stacked promotion against a single flat discount honestly. The “you pay” row is simply the final price divided by the original one, expressed as a percentage of the original price.

Formula

Final price = Price × (1 − d1) × (1 − d2)…
You save = Price − Final price

Where:

  • Price — the original price before any discount
  • d₁, d₂ — discount rates as decimals (25% = 0.25), applied in order
  • Effective discount = 1 − (final ÷ original)

Example

A $80 jacket at 25% off: the discount is 80 × 0.25 = $20, so the final price is $60 and you pay 75% of the original. Add a members-only extra 10%: the second cut removes 10% of $60 — another $6 — landing at $54. The effective discount is 32.5%, not 35%: the labels overstate the deal by 2.5 points, which the effective row makes obvious.

Frequently Asked Questions

Why don't two discounts add up to their sum?
Because the second percentage applies to a smaller base. After the first discount reduces the price, the second discount takes a share of the reduced figure. 30% then 10% equals 37% effective — the missing 3 points are the discount that would have been applied to money you already saved.
Is a bigger single discount always better than a stacked one?
Compare effective discounts, not labels. A flat 40% beats 30% + 10% (37% effective). But 25% + 15% also equals 36.25%, so a stacked offer can genuinely match or beat a flat one — calculate rather than guess.
Does the calculator handle “buy one get one half off”?
Not directly, because those offers depend on quantities. You can approximate: two items at half price on the second equals 25% off the pair — enter the combined price with a 25% discount.
What about discounts plus sales tax?
Tax is normally applied to the already-discounted price. Calculate the discount first, then use the VAT calculator on the result if you want to see the true out-the-door total.