Quick answer
The sale price is the original price times (1 − discount). When a second discount follows, multiply again: price × (1 − d₁) × (1 − d₂). 25% off $80 is $60; 30% off followed by a further 20% off is 44% off in total, not 50%.
Successive discounts apply to the already reduced price, so they compound instead of adding. The order does not change the final price.
Related tools: Tip Calculator: Tip, total and per-person share. Depreciation Calculator: Straight-line depreciation schedule. Decimal to Hex Converter: Convert integers between binary, octal, decimal and hexadecimal.
How to use the Discount Calculator
- Enter original price ($) (0 or more).
- Enter discount (%) (between 0 and 100).
- Optionally, enter additional discount (%) (between 0 and 100).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Original price | A number, in $ | ≥ 0 |
| Discount | A number, in % | ≥ 0, ≤ 100 |
| Additional discount (optional) | A number, in % | ≥ 0, ≤ 100 |
Formula and method
Formula
final = price × (1 − d₁) × (1 − d₂)
IEEE-754 double precision; money shown to cents, rates to 4 decimals. Results are estimates, not financial advice.
Discounts are applied one after the other, not added together.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Original price = 80; Discount = 25.
| Result | Value |
|---|---|
| Final price | $60.00 |
| You save | $20.00 |
| Effective discount | 25% |
Example 2
Inputs: Original price = 100; Discount = 20; Additional discount = 10.
| Result | Value |
|---|---|
| Final price | $72.00 |
| You save | $28.00 |
| Effective discount | 28% |
The first line is the headline result (final price). Below it the discount Calculator lists you save and effective discount, which describe the same case from other angles. IEEE-754 double precision; money shown to cents, rates to 4 decimals. Results are estimates, not financial advice.
Combining two discounts
Two discounts of a% and b% combine into a single discount of a + b − (a × b ÷ 100) percent. For 30% and 20% that is 30 + 20 − 6 = 44%, so a $100 item costs $56. Reversing the order gives the same $56.
Three or more discounts, and finding the discount from two prices
The calculator takes two discounts, but the rule extends: multiply the price by (1 − d) for each one. 10%, 20% and 30% off a $100 item gives 100 × 0.9 × 0.8 × 0.7 = $50.40, a total discount of 49.6%.
To find the discount when you only know the original and final prices, use 1 − final ÷ original. A jacket marked down from $80 to $60 is 1 − 60 ÷ 80 = 25% off.
A $100 item with 30% off and a second discount
Every figure in this table comes from running this calculator, so it matches what the form returns.
| Second discount (%) | Final price | Effective discount |
|---|---|---|
| 0 | $70.00 | 30% |
| 10 | $63.00 | 37% |
| 20 | $56.00 | 44% |
| 30 | $49.00 | 51% |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Discount: entering "120" shows "Discount must be at most 100." beside that field and no result.
Choosing between the Discount Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Tip Calculator](/finance/tip-calculator/) | bill amount, tip and split between | Tip |
| [Depreciation Calculator](/finance/depreciation/) | asset cost, salvage value and useful life | Annual depreciation |
| [Decimal to Hex Converter](/technology/decimal-to-hex-calculator/) | input base and value | Hexadecimal |
| [Pixels Per Inch (PPI) Calculator](/technology/pixels-per-inch/) | horizontal pixels, vertical pixels and diagonal size | Pixel density |
| [Efficiency Calculator](/engineering/efficiency/) | useful output and input | Efficiency |
Background: personal finance estimates
Financial calculators project from the numbers you give them. Long-range tools depend on guesses about returns and tax rates that are unlikely to hold exactly, payoff tools assume a fixed payment and rate, and tax or salary results depend on the tax year, filing status and country. Official calculators say their output is for reference only.
For decisions that matter, use conservative inputs and check the figures against your lender, plan documents or a qualified adviser.
Assumptions and limitations
- 100% gives a free item
Results are estimates for planning, not financial advice. Lender terms, fees, taxes and rounding rules can change real figures, so confirm important numbers with your lender or a licensed adviser.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for discount to confirm this.
Frequently asked questions
Is 30% off plus 20% off the same as 50% off?
No. The second discount applies to the reduced price, so the total is 44% off.
What does the Discount Calculator calculate?
Final price after one or two successive discounts. It returns Final price, You save and Effective discount.
What formula does the Discount Calculator use?
final = price × (1 − d₁) × (1 − d₂). Discounts are applied one after the other, not added together.
What do I need to enter in the discount Calculator?
You enter Original price ($) and Discount (%). Optional: Additional discount (%).
How is the result rounded or limited?
IEEE-754 double precision; money shown to cents, rates to 4 decimals. Results are estimates, not financial advice. 100% gives a free item.
What is an example of a discount result?
With original price 80 and discount 25, the final price is $60.00.
Can I rely on this calculator for a decision?
Results are estimates for planning, not financial advice. Lender terms, fees, taxes and rounding rules can change real figures, so confirm important numbers with your lender or a licensed adviser. For this calculator in particular: 100% gives a free item.
Related calculators
- Tip Calculator — Tip, total and per-person share.
- Depreciation Calculator — Straight-line depreciation schedule.
- Decimal to Hex Converter — Convert integers between binary, octal, decimal and hexadecimal.
- Pixels Per Inch (PPI) Calculator — Pixel density of a display.
- Efficiency Calculator — Efficiency as output divided by input.
- Auto Loan Calculator — Monthly car payment after down payment and trade-in.
Sources
- Standard time-value-of-money relations (e.g. Brealey, Myers & Allen, Principles of Corporate Finance)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.