Discounts Stack in Order

Stores apply their discount first, coupons second, and tax last — and the order changes the math. A 20% sale with a 10% coupon is 20% off, then 10% off the remainder: 28% total, not 30%. Because tax is charged on the discounted price, the final number almost always lands below the "original minus sticker discount" estimate shoppers do in their heads.

The Savings Percentage Is the Truth

Advertised discounts refer to the original price, but the number that matters is what you keep versus what the register charges. With tax included, a 20% sale on a $120 item in an 8% tax state saves $28.99 — about 24% of the original. The calculator reports both the dollar savings and the true percentage so you can compare deals across different tax rates.

Price Anchoring Works on You

Retailers set high "original" prices to make discounts look larger, and .99 endings to make prices feel smaller. The defense is arithmetic: compute the final all-in price and compare it to the same item's history and competitors. If the "sale" price equals what you'd pay anywhere else, the discount is decoration — not a deal.