Discount Calculator

The Discount Calculator works out exactly what you'll pay after one or more percentage-off discounts are applied, including the case that trips up mental math the most: stacked discounts, like an extra 10% off an already-discounted item. Enter the original price, add one or more discount percentages, and optionally a tax rate applied after the discounts, and the tool shows the final price along with your total savings and the effective discount percentage.

The key detail is that stacked discounts multiply, they don't add. "20% off, then an extra 10% off" is not a 30% discount — it's 28%, because the second discount applies to the already-reduced price, not the original one. This calculator applies each discount sequentially to the running price, exactly the way a retailer's checkout system does, so the final number matches what you'd actually pay rather than a back-of-envelope estimate that adds percentages together.

Add as many stacked discounts as the situation calls for — a coupon on top of a clearance sale on top of a loyalty discount — using the "Add another discount" button, and remove any of them individually. If sales tax applies after discounts (as it does in most places), enter that rate too, and it's calculated on the post-discount price, matching how receipts are actually itemized.

Everything recalculates instantly as you adjust any field, entirely in your browser. This is a general-purpose shopping and pricing calculator — for anything involving invoicing, GST-specific tax rules, or business accounting, pair it with the GST Calculator or Invoice Generator for the compliance-specific parts of the math. It's equally useful for shoppers comparing whether a coupon code is actually worth applying and for small sellers working out a sale price that still covers costs after stacking a seasonal discount on top of a clearance markdown.