Here’s a piece of retail math that trips almost everyone: an item is 25% off, and you have a coupon for an extra 20% off. That’s 45% off, right? It isn’t — it’s 40%, because the second discount applies to the already-reduced price.
Our new discount calculator does that math correctly, instantly:
- Final price — after one discount, a stacked second discount, and optional sales tax (applied to the discounted price, as most US states do).
- Total saved — in dollars, against the original price.
- Effective discount — the whole stack expressed as one honest percentage, so “25% + 20%” shows its true 40%.
Try the example: $120 at 25% off is $90; stack 20% more and you land at $72. Everything runs in your browser, your inputs live in the URL for sharing, and there’s an embeddable version for shopping and deals blogs.