Extra coupons stack multiplicatively — 20% off, then an extra 10% coupon means 28% total off, not 30%.
Discount Calculator — Free Online Tool
See the final price and exactly how much you save — stack an extra coupon discount too. Everything updates live, right in your browser.
How it works
Frequently asked questions
How are the discount and the extra coupon combined?
Multiplicatively, exactly like real stores do — the second discount applies to the already-discounted price, not the original. So 20% off plus an extra 10% coupon is 28% total off (1 − 0.80 × 0.90 = 0.28), not 30%.
Is my data uploaded to a server?
No. Every calculation happens with plain JavaScript in your browser — your prices never leave this page, and nothing is stored anywhere.
Which currency does the calculator use?
₹ by default. The tool is currency-neutral — the maths is identical for any currency, so just read ₹ as your own currency symbol.
Stacked discounts multiply · 100% local — your numbers never leave this page.