Sale price after a percent or flat discount, with optional tax.
Sale = original × (1 − discount %), or original − flat amount. Tax is applied to the discounted price (post-discount tax).
Sale tags are designed to feel exciting, not to be exact. "30 % off!", "Take an extra €20!", "−40 % on selected items, plus 20 % VAT at checkout!" Most shoppers do the math in their head and get it wrong by a few percentage points — fine for a single coffee, costly when you're stacking discounts on a big-ticket purchase. This calculator handles all four common cases: percent off, flat amount off, with or without sales tax/VAT applied to the discounted price. It also reports the effective discount percentage when you enter a flat amount, so you can compare a "20 € off" coupon against a "15 % off" coupon on the same item.
Percent off: sale = original × (1 − pct/100). Flat amount: sale = max(0, original − amount); the calculator clamps so a 25 € discount on a 20 € item produces a free item, not a negative price. Effective discount % = (original − sale) / original × 100, useful when you punched in a flat amount and want the equivalent rate. Tax: if a tax rate is given, tax = sale × rate / 100, and final = sale + tax. Tax is applied to the post-discount price — the standard treatment everywhere except a few US jurisdictions that tax pre-discount; if you live in one of those, treat the post-tax line as a lower bound and add the local rule manually.
Enter the original price, pick the discount type (percent off or flat amount), enter the discount value, and optionally enter a sales tax / VAT percentage. The calc shows: the sale price (before tax), the amount you save, the effective discount percentage, the tax amount, and the final price out of the door. If you don't shop in a tax-applied jurisdiction (US most cases), leave tax at 0 — the "final" line will equal the "sale" line.
A jacket originally priced at 120 € with 30 % off, French VAT 20 % already in the displayed price (no tax to add). - Sale: 120 × 0.70 = 84.00 €. - You save: 36.00 € (30 % effective). - Final: 84.00 € (tax already in the displayed price, rate left at 0).
Same jacket as a US item priced $120 pre-tax, 30 % off, 8.5 % sales tax. - Sale: $120 × 0.70 = $84.00. - Tax: 84 × 0.085 = $7.14. - Final: $91.14.
Stacked discounts. Two coupons of 20 % each are not 40 % off, they're 36 % off (1 − 0.8 × 0.8). If your coupon says "extra 20 % off the sale price" and the item is already 30 % off, the calc supports this — chain it: first compute 30 % off, then re-enter the result as the original price and apply the 20 % off. Most retailers add coupons in this multiplicative way; some special promotions add them additively (rare). Read the small print.
Flat amount on a percentage display. If the tag says "−€20" but you enter that into a "percent off" field as 20 you'll undercount the discount on cheap items and overcount it on expensive ones. Toggle to Flat amount when in doubt.
Tax-inclusive vs tax-exclusive prices. EU/UK prices nearly always include VAT in the shelf price (no tax to add). US prices nearly always exclude state/local sales tax. The calc cannot infer which regime you're in — leave the tax rate at 0 if the displayed price already includes tax.
Negative discount. Entering a discount larger than the original (e.g. 110 % off) produces a sale price of 0; the saving is capped at the original. Combinations of discount > tax pre-application can produce surprising final-with-tax values that exceed the sale price — they shouldn't, the math is correct, but a refunded-tax workflow on the seller's side might recover that delta later.
Decimal vs comma. The form uses HTML number inputs, which accept both depending on the OS locale. If a parsed value comes out as 0 unexpectedly, check whether your keyboard layout used a thousand separator the input rejected.