Discount Calculator
Use this free Discount Calculator to calculate sale price, discount amount, total savings, discount percentage and original price. Quickly find out how much you save on a sale, coupon or percentage-off deal.
Calculate Discounts and Sale Prices
1. Calculate Sale Price and Savings
2. Calculate Discount Percentage
3. Calculate Original Price
What Is a Discount?
A discount is a reduction from an original or listed price. Discounts are commonly expressed as a percentage, such as 10% off, 20% off, 25% off or 50% off.
When a product has a percentage discount, the discount amount is calculated from the original price. The discount amount is then subtracted from the original price to determine the final sale price.
Discount Calculator Formula
There are several useful discount formulas depending on which values are known.
Formula 1: Calculate Discount Amount
Formula 2: Calculate Sale Price
Formula 3: Calculate Discount Percentage
Formula 4: Calculate Original Price
How to Calculate a Discount
To calculate a percentage discount manually, first convert the percentage into a decimal by dividing it by 100. Multiply the original price by this decimal to find the amount saved. Finally, subtract the savings from the original price.
Discount amount = $200 × (25 ÷ 100)
Discount amount = $50
Sale price = $200 − $50
Final sale price = $150How to Calculate Sale Price
The fastest way to calculate the final price after a percentage discount is to multiply the original price by the percentage you actually pay.
For example, after a 25% discount, you pay 75% of the original price.
Original price = $80
Discount = 25%
You pay = 75%
$80 × 0.75 = $60
You save $20 and pay $60.Common Discount Percentages
| Discount | You Pay | Multiplier |
|---|---|---|
| 10% off | 90% | 0.90 |
| 15% off | 85% | 0.85 |
| 20% off | 80% | 0.80 |
| 25% off | 75% | 0.75 |
| 30% off | 70% | 0.70 |
| 40% off | 60% | 0.60 |
| 50% off | 50% | 0.50 |
| 70% off | 30% | 0.30 |
| 80% off | 20% | 0.20 |
| 90% off | 10% | 0.10 |
How to Calculate Discount Percentage From Two Prices
If you know the original price and the sale price but do not know the advertised discount percentage, you can calculate the discount by finding the amount saved first.
Amount saved = $150 − $120 = $30
Discount percentage = ($30 ÷ $150) × 100
Discount percentage = 20%How to Find the Original Price From a Sale Price
Finding the original price is different from simply adding the discount percentage back to the sale price. The discount was originally calculated from the higher original price.
Remaining percentage = 100% − 25% = 75%
Original price = $60 ÷ 0.75
Original price = $80Simply adding 25% to $60 would produce $75, which is not the correct original price. The correct reverse calculation requires division by the percentage remaining.
Stacked Discounts
Multiple percentage discounts applied one after another should not normally be added together.
Start with $100.
After 20% off: $100 × 0.80 = $80
After another 10% off: $80 × 0.90 = $72
Total savings = $100 − $72 = $28
Effective discount = 28%, not 30%The second discount is calculated from the already reduced price. Therefore, two successive discounts of 20% and 10% produce a combined effective discount of 28%.
Discount vs Percentage Decrease
A percentage discount on a product price is mathematically a percentage decrease from the original price. The original price is the reference value, and the discount represents the percentage by which that price is reduced.
For example, reducing a $200 price to $150 represents a $50 reduction. Since $50 is 25% of $200, the percentage discount is 25%.
Discounts in Shopping and Retail
Discount calculations are commonly used when comparing sale prices, checking promotional offers, applying coupons and estimating shopping savings.
- Retail store sales
- Online shopping discounts
- Coupon and promotional codes
- Black Friday and seasonal sales
- Clearance discounts
- Wholesale price reductions
- Membership discounts
- Bulk purchase discounts
- Business purchasing decisions
- Budget planning
Discount Amount vs Sale Price
The discount amount and sale price are two different results. The discount amount tells you how much money was saved, while the sale price tells you how much remains to be paid before any additional taxes, fees or charges.
For example, if a $500 product has a 20% discount, the discount amount is $100 and the sale price is $400.
Does Tax Apply Before or After a Discount?
Tax treatment varies by country, product and applicable tax rules. This calculator focuses on the percentage discount itself and does not automatically calculate sales tax or VAT.
If tax or VAT is involved, check the applicable rules for your location to determine whether the tax is calculated on the original price, discounted price or another taxable amount.
Common Discount Calculation Mistakes
- Adding the discount percentage directly to the sale price to find the original price.
- Treating two successive discounts as if their percentages simply add together.
- Multiplying the original price by 25 instead of converting 25% to 0.25.
- Confusing the discount amount with the final sale price.
- Using the sale price rather than the original price as the base when calculating the discount percentage.
Frequently Asked Questions
How do I calculate a discount?
Multiply the original price by the discount percentage divided by 100 to find the discount amount. Then subtract the discount amount from the original price to find the sale price.
What is the formula for sale price after a discount?
Sale Price = Original Price × (1 − Discount Percentage ÷ 100).
How do I calculate the discount percentage from two prices?
Discount Percentage = ((Original Price − Sale Price) ÷ Original Price) × 100.
How do I find the original price from a sale price?
If you know the sale price and discount percentage, divide the sale price by 1 minus the discount percentage divided by 100.
What is 20% off $100?
A 20% discount on $100 saves $20, so the final sale price is $80.
What is 25% off $200?
A 25% discount on $200 saves $50, so the final sale price is $150.
Do two discounts of 20% and 10% equal a 30% discount?
No. When discounts are applied one after another, the second discount is applied to the already reduced price. For example, 20% followed by 10% produces an effective discount of 28%.
Can a discount be more than 100%?
A normal price discount cannot meaningfully exceed 100%, because a 100% discount reduces the price to zero.
Is a discount the same as a percentage decrease?
For a price reduction, a percentage discount uses the same mathematical concept as a percentage decrease, with the original price serving as the reference value.
Is this discount calculator free?
Yes. Smart Unit Calc provides this discount calculator free to use online.