Shopping utility

Discount Calculator

Work out a single markdown, stacked discounts, tax, and the real amount you save before checkout.

Sale price breakdown

Price after first discount$0.00
Price after stacked discounts$0.00
Tax amount$0.00
Final price$0.00
Total savings$0.00
Effective discount0.0%

Formula

sale = original x (1 - d1) x (1 - d2)

tax = sale x taxRate

final = sale + tax

Quick examples

  • $80 with 20% off becomes $64 before tax.
  • Stacking 20% and 10% off is not the same as 30% off.
  • A higher tax rate changes the checkout total, not the savings amount.

How it works

The calculator applies each discount in sequence. If you enter a second discount, it is taken from the already discounted price rather than from the original price. Tax is then added to the sale price.

This matters because stacked discounts compound. A 25% discount followed by a 10% discount produces an effective markdown of 32.5%, not 35%.

Use this for coupon math, clearance comparisons, and checking whether a second promotion actually changes the total enough to matter.