Finance

Discount Calculator

Enter the original price and discount percentage to see the sale price and how much you save — handy for sales, coupons, and comparing deals.

Calculate

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Updates as you type

Result

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The formula

A percentage discount multiplies the original price by the remaining share (1 − discount%). Savings equal original minus sale price.

Sale = Original × (1 − Discount% ÷ 100) · Saved = Original − Sale

Worked example

  1. Original $100, discount 20%
  2. Sale = $100 × (1 − 0.20) = $80
  3. Saved = $100 − $80 = $20

Result: Sale $80 · saved $20

How the discount is applied

This calculator applies one percentage off the price you enter. Real checkouts may add tax, stack coupons, or round differently.

Single percentage off

Sale price = original × (1 − d/100). A 25% discount leaves 75% of the original. Savings are the complement: original × d/100.

Stacked discounts are multiplicative

Two successive discounts multiply remaining factors. 20% off then 10% off → 0.80 × 0.90 = 0.72 of original (28% total off), not 30%. Apply one combined equivalent % here, or run the calculator twice.

Tax and “was” prices

In many U.S. states, sales tax applies to the discounted price. Advertised “was” prices can be anchors — compare the final checkout total. We do not validate whether a strike-through price is a fair reference.

What we do not model

No BOGO logic, fixed-amount coupons ($10 off), shipping, or loyalty points. Convert those to an equivalent percentage first if you want a single % input.

Interesting facts

Black Friday math

A 20% off plus another 10% off is not 30% off — successive discounts multiply. After 20%, only 80% remains; 10% of that leaves 72% of the original price.

Markup vs margin

A 50% markup on cost is not a 50% profit margin. Margin divides profit by selling price; markup divides by cost.

Anchor prices

Retailers often show a higher “was” price to frame the deal. Compare the final checkout total, not only the flashy percentage.

Sales tax after discount

In many U.S. states, sales tax applies to the discounted price. Always check whether tax is included in the advertised total.

Coupon stacking rules

Store and manufacturer coupons may or may not combine. Read the fine print — “cannot be combined” is common.

Frequently asked questions

Multiply the original price by (1 − discount%/100). Example: $100 with 20% off → $80. The calculator also shows dollars saved.

Saved ÷ original × 100. If you know original and sale: (($100 − $80) ÷ $100) × 100 = 20%. Use the percentage calculator for reverse cases.

No. Apply them one after another (multiply the remaining fractions). 15% then 10% leaves 0.85 × 0.90 = 76.5% of the original price.

No. Enter a tax-exclusive price to get a pre-tax sale amount, then add local tax separately if needed.

Subtract the fixed amount from the price first (or after a %-off, depending on store rules), then optionally convert the combined deal to an equivalent percentage.

References

  1. Percentage — NIST SI education — National Institute of Standards and Technology (NIST) Authoritative guidance on expressing quantities; percent is a ratio × 100.
  2. Sales tax basics — U.S. Internal Revenue Service / state tax agencies Federal context for sales tax; actual rates and bases are set by states and localities.
  3. Consumer shopping tips — Federal Trade Commission (FTC) Practical guidance for evaluating online offers and checkout totals.