Double Discount Calculator
Stacked discounts and the real saving.
Enter your values
Enter the original price in $.
Enter the first discount in %.
Enter the second discount in %.
Enter the sales tax in %.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Final price
- $67.20
- Price before tax
- $67.20
- You save
- $52.80
- Effective discount
- 44%
- Naive sum of discounts
- 50%
Quick answer
Stacked discounts multiply rather than add — 30% off then 20% off is 44% off, not 50%.
Final = P × (1 − d1) × (1 − d2)
At a glance
| What it does | Stacked discounts and the real saving. |
|---|---|
| Category | Everyday |
| Inputs needed | Original price, First discount, Second discount, Sales tax |
| Main output | Final price |
| Formula | Final = P × (1 − d1) × (1 − d2) |
| Cost | Free — no sign-up, no download |
How to use the Double Discount Calculator
- 1Enter the original ticket price.
- 2Enter both discount percentages.
- 3Add sales tax if you want the checkout total.
Inputs explained
- Original price($)
- Enter the original price in $.
- First discount(%)
- Enter the first discount in %.
- Second discount(%)
- Enter the second discount in %.
- Sales tax(%)
- Enter the sales tax in %.
Worked example
Using the values the calculator loads with:
Inputs
- Original price120 $
- First discount30 %
- Second discount20 %
- Sales tax0 %
Results
- Final price$67.20
- Price before tax$67.20
- You save$52.80
- Effective discount44%
- Naive sum of discounts50%
Frequently asked questions
Why isn't 30% + 20% equal to 50%?
The second discount applies to the already-reduced price, so it removes less money.
Does order matter?
No — multiplication is commutative, the final price is identical either way.
What do I need to enter into the Double Discount Calculator?
Just 4 values: original price, first discount, second discount, sales tax. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Double Discount Calculator work out the answer?
Stacked discounts multiply rather than add — 30% off then 20% off is 44% off, not 50%. It applies the formula Final = P × (1 − d1) × (1 − d2) and shows the working so you can check each step by hand.
Is the Double Discount Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.