Double Discount Calculator
Calculate the final price after two stacked discounts and the true combined discount percentage.
Your inputs
Results
Final price
$112.00
- Combined discount
- 44%
- Not the same as adding them
- 50% would be 6 points more
- Price after first discount
- $140.00
- Total saved
- $88.00
✓Exact calculation — rounded only for display
What this calculator does
“30 % off, plus an extra 20 % off” is not 50 % off. The second discount applies to the already reduced price.
Formula and method
Final = price × (1 − d₁) × (1 − d₂); Combined = 1 − (1 − d₁)(1 − d₂)
Worked example
Calculated by this tool with its default inputs:
Inputs
- Original price: 200 (any currency)
- First discount: 30 %
- Additional discount: 20 %
Results
- Final price: 112
- Combined discount: 44%
- Not the same as adding them: 50% would be 6 points more
- Price after first discount: 140
- Total saved: 88
How to read the results
30 % then 20 % is a 44 % combined discount, not 50 %.
Assumptions and limitations
- The order of the discounts does not change the result.
Questions
Is stacking worse than one big discount?
Two discounts of p and q are always less than a single discount of p + q.
Methodology and verification
- Result type
- Exact mathematical calculation (rounded only for display)
- Formula version
- 1.0
- Automated verification
- 3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy