Discount Calculator
Enter a price and a discount to see the sale price, your saving, and the effect of an extra discount or tax.
What this tool does
A discount calculator gives the price after a percentage off. Enter the original price and the discount, and it shows the sale price and the amount saved. You can add a second discount, applied after the first, and a tax rate to see the final price at the checkout.
Takes a percentage off the original price, optionally takes a second percentage off the result, and adds tax if you enter a rate.
Shows the amount saved and the effective overall discount, so stacked offers are not mistaken for their sum.
How to use it
- Choose a currency symbol if you want one.
- Enter the original price.
- Enter the discount percentage.
- Enter an extra discount if there is a second offer, and a tax rate if tax is added at checkout.
- Read the price after discount, your saving and the effective discount.
Why use a discount calculator
Applies a second, extra discount after the first, which is how "extra 10% off sale prices" actually works. Shops advertise percentages, but what matters is the amount you pay. Stacked offers are the main source of confusion: 25% off and then 10% off is 32.5% off, not 35%.
Why we built it
We built the discount calculator to apply a second, extra discount after the first, which is how stacked offers really work and why two 20% discounts are not 40% off. The percentage calculator covers other percentage questions, and the VAT calculator adds or removes tax from the sale price.
Who this tool is for
- Shoppers comparing sale prices
- Shop owners setting promotions
- Anyone working out "extra 10% off" offers
When to use it
- Comparing two sales with different percentages.
- Checking what an advert for extra money off really costs.
- Working out the price including tax before you check out.
- Seeing how much you save on a large purchase.
How it is calculated
Price after a discount is price × (1 − discount ÷ 100). A second discount is applied to that result. Tax is then price × (1 + tax ÷ 100).
Worked example: 100 with 25% off is 75. A further 10% off is 67.50. Together that is 32.5% off, not 35%.
The order of percentage discounts does not change the final price, but a fixed amount off and a percentage off do depend on the order.
What you enter, and what you get back
| Item | Details |
|---|---|
| Original price | The price before any discount. |
| Discount and extra discount | Two percentages, applied one after the other. |
| Tax | Added to the discounted price. |
| Result | Final price, amount saved, effective discount. |
Issues you may run into
| What you see | Why it happens | What to do |
|---|---|---|
| Saving smaller than expected | Stacked percentages were added together. | They compound; see the effective discount. |
| Price differs at checkout | Tax or delivery was added. | Enter the tax rate; delivery is not included. |
| 100% off | A discount of 100% gives a price of zero. | Check the percentage you entered. |
A worked example
These are the values the calculator opens with, so you can see exactly what it does with them. Change any value on the page and the result updates; the figures below come from the same calculation.
| Input | Value |
|---|---|
| Currency symbol | $ (dollar) |
| Original price | 120 |
| Discount | 25 % |
| Extra discount | 0 % |
| Tax added at checkout | 0 % |
With those inputs, the calculator returns:
- Price after discount: $90.00
- You save: $30.00
- Effective discount: 25.00%
- Price before tax: $90.00
Assumptions and limitations
- Percentage discounts only; a fixed amount off is not modelled.
- Delivery and other fees are not included.
- Rounding to the nearest unit may differ by a cent from a shop’s system.
- Tax is a single flat rate.
Frequently asked questions
How do I calculate a discount?
Multiply the price by the discount percentage divided by 100 to get the saving, then subtract it. Or multiply the price by (1 − discount ÷ 100).
How do two discounts add up?
They compound. 25% off then 10% off is 32.5% off, because the second percentage applies to the already reduced price.
How do I include tax?
Enter the tax rate and the calculator adds it to the discounted price, giving the amount you pay.
What is 20% off 50?
20% of 50 is 10, so the sale price is 40.
Does the order of discounts matter?
Not for two percentage discounts - the result is the same either way.