Finance tools
Discount calculator
Free discount calculator and percent off calculator for shoppers and small businesses. Enter an original price and discount for live sale price, savings, and effective discount % — or find the discount %, work back to the original price, or model stacked / double discounts. Choose percent off or a fixed coupon amount. Presets for 10%, 20%, 25%, and 50% off. For generic percent math, see our percentage calculator. No submit button. Export CSV or PDF when you are done.
What this discount calculator does
A discount reduces the price you pay. Most sale tags show a percentage off the original price; coupons often subtract a fixed dollar amount. This sale price calculator shows final price, amount saved, and effective discount % in real time.
Four modes cover the questions people search most: what is the sale price, how to calculate discount percentage from two prices, what was the original price before a sale, and how double discounts combine when applied one after another.
Final price (default)
Original price + percent or fixed off → sale price and savings.
Find discount %
Original and final price → discount percentage.
Find original price
Final price + known discount → list price before the sale.
Stacked discounts
Two sequential % off — not added together (20% then 10% ≠ 30%).
Discount formula
For a percentage discount, multiply the original price by the discount rate, then subtract that amount from the original price.
Percent off
Savings = Original price × (Discount % ÷ 100)
Final price = Original price − Savings
Example: $100 with 20% off → savings $20 → final price $80.
Fixed amount off
Final price = Original price − Fixed discount — e.g. $95 − $20 coupon = $75.
Percent off calculator shortcuts
You do not always need a full formula. For common percent off deals, multiply the original price by the percentage you still pay (100% minus the discount).
| Discount | Shortcut | On $100 | On $50 |
|---|---|---|---|
| 10% off | × 0.90 | $90 | $45 |
| 15% off | × 0.85 | $85 | $42.50 |
| 20% off | × 0.80 | $80 | $40 |
| 25% off | × 0.75 | $75 | $37.50 |
| 50% off | ÷ 2 (half price) | $50 | $25 |
20% off in one step
20% off $25 → multiply by 0.80 → $20 sale price (save $5).
Use the calculator presets or enter any price above — results update as you type.
How to find the original price
If you know the sale price and the discount percentage, divide the final price by the percentage you still pay:
Original price = Final price ÷ (1 − Discount % ÷ 100)
Example: Final price $80 after 20% off → $80 ÷ 0.80 = $100 original.
Stacked & double discounts
A double discount (or stacked discount) applies one deal after another to the already reduced price. When a store offers 20% off and then an extra 10% off, you do not add the percentages to get 30% off.
| Step | Calculation | Price |
|---|---|---|
| Original | — | $100.00 |
| After 20% off | $100 × 0.80 | $80.00 |
| After extra 10% off | $80 × 0.90 | $72.00 |
| Total saved | $100 − $72 | $28.00 (28% effective) |
Not additive
20% + 10% stacked = 28% effective discount, not 30%. The results panel shows effective discount % so you can compare deals. Use the Stacked tab to model two sequential percent-off deals.
Discount vs markup
A discount lowers the price a customer pays from a listed or original price. Markup is what a business adds on top of cost to set a selling price — the opposite direction. If you price products from COGS, use our markup calculator instead.
Tax after discounts
In most checkout situations, sales tax applies to the discounted price, not the pre-sale list price. Rules vary by state and product type — check your receipt when exact tax matters.
To estimate tax on a sale price, use our sales tax calculator. This discount tool does not add tax — it focuses on the discount math only.
How to use this discount calculator
Pick a calculation mode
Choose Final price (default), Find discount %, Find original price, or Stacked for two sequential percent-off deals.
Enter price and discount
Type the original or final price and set percent off or a fixed coupon amount. Use presets (10%, 20%, 25%, 50%) for quick percent-off math.
Read sale price, savings, and export
Results update live — final price, amount saved, and effective discount %. Export CSV or PDF when you are done.
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Frequently asked questions about this discount calculator
How do you calculate a discount?
Multiply the original price by the discount percentage, then subtract that amount from the original price. Example: 20% off $100 → save $20 → pay $80. Use Final price mode above.
How do you calculate 20% off a price?
Multiply the price by 0.20 to get the savings, then subtract from the original. 20% off $100 → $20 saved → $80 final price. Quick presets (10%, 20%, 25%, 50%) are available in the calculator.
What is the discount formula?
Savings = Original price × (Discount % ÷ 100) and Final price = Original price − Savings. For a fixed coupon: Final price = Original price − Fixed amount.
How do I find the original price before a discount?
Divide the final price by (1 − discount % ÷ 100). Example: $80 after 20% off → $80 ÷ 0.80 = $100 original. Use Find original price mode.
How do I calculate the discount percentage from two prices?
Discount % = ((Original − Final) ÷ Original) × 100. Example: $50 down to $40 → ($10 ÷ $50) × 100 = 20% off. Use Find discount % mode.
What is the difference between a percentage discount and a fixed amount off?
A percentage discount scales with price (20% off $100 saves $20; 20% off $50 saves $10). A fixed amount subtracts the same dollars regardless of price ($20 off any item). Toggle discount type in Final price or Find original price mode.
How do stacked or double discounts work?
Stacked (double) discounts apply one after another to the remaining price. 20% off then 10% off $100 → $80 after the first discount → $72 final (28% effective), not $70. Use the Stacked tab — percentages are not added together.
What is effective discount percent?
Effective discount % = (total savings ÷ original price) × 100. It is useful for comparing stacked deals or mixed promotions. Example: $100 → $72 after 20% then 10% off → save $28 → 28% effective discount. The calculator shows this on every result.
How much is 10% off a price?
Multiply the original price by 0.10 to get savings, then subtract — or multiply by 0.90 for the sale price directly. 10% off $50 → save $5 → pay $45. 10% off $100 → $90.
Is 50% off the same as half price?
Yes. A 50% discount means you pay half the original price. Example: 50% off $80 → $40.
Should tax be calculated before or after a discount?
Usually after the discount is applied. Tax is calculated on the price you actually pay at checkout. For state sales tax estimates on a discounted price, see our sales tax calculator.
Is this discount calculator free?
Yes. Live results with optional CSV and PDF export — no sign-up required. For general percent-of and percent-change questions, try our percentage calculator.