Calculate the final price after any discount and see exactly how much you save. Add optional sales tax to get the true checkout total. Perfect for shopping, pricing, and sales planning.
Calculating a discount involves two steps. First, find the discount amount: Discount Amount = Original Price × (Discount % ÷ 100). Then subtract it from the original price to find the sale price: Sale Price = Original Price − Discount Amount. If sales tax applies, it's typically calculated on the discounted price, not the original price: Tax Amount = Sale Price × (Tax Rate ÷ 100).
Stack discounts carefully — they don't simply add together. A 20% discount followed by an additional 10% discount is NOT a 30% discount. On a $100 item: 20% off = $80, then 10% off $80 = $72. The total effective discount is 28%, not 30%. This is called a cascading discount and is commonly used in clearance pricing.
Example 1 (Standard discount): $150 jacket at 30% off. Save = $150 × 0.30 = $45. Sale price = $105. With 8% sales tax: $105 × 0.08 = $8.40. Total = $113.40.
Example 2 (Electronics sale): $899 laptop at 15% off. Save = $899 × 0.15 = $134.85. Sale price = $764.15. A coupon for an additional $50 off makes final price $714.15.
Example 3 (Clearance): $200 item marked down 40% then an additional 25% off the sale price. First discount: $200 × 0.40 = $80 off → $120. Second discount: $120 × 0.25 = $30 off → $90 final price. Effective discount = 55%, not 65%.
Smart shopping tips: calculate the per-unit price for bulk discounts (a 10-pack at $8.99 vs a 6-pack at $5.49 — which is cheaper per unit?); don't buy something you don't need just because it's discounted; factor in sales tax because a 20%-off sale in a 10% tax state results in a net effective saving of only 12.7%; and use this calculator before checkout to verify that the advertised discount is actually being applied correctly.
In the United States, sales tax is calculated on the post-discount price. So a 20% discount on a $100 item brings it to $80, and then tax is applied to $80, not $100. This means discounts and tax don't cancel each other out directly — the discount saves you more than you might expect when tax is involved.
If you know the sale price and the discount percentage, reverse the calculation: Original Price = Sale Price ÷ (1 − Discount Rate). Example: a $63 sale price after 30% off means original = $63 ÷ 0.70 = $90.
Buy One Get One Free (BOGO) is effectively a 50% discount. Buy One Get One 50% off is a 25% discount on the total purchase (you pay full price for one and half price for the other). Always calculate the effective per-item price to compare BOGO deals with straight percentage discounts.
Research shows that many retailers artificially inflate the 'original' price to make discounts appear larger. The FTC requires that advertised reference prices must be genuine former prices the item was actually sold at. If you see an unusually large discount on a product that's new to market, the reference price may not reflect actual prior sales.
Employee discounts typically apply as a percentage off the retail price, similar to customer promotions. Some employers offer discounts on wholesale or cost price plus a small markup. The discount is usually applied before taxes and the taxable income implications (if the discount exceeds certain IRS thresholds) vary by country and employer policy.