Discount Calculator
Calculate the final price after a discount (with optional tax), or work out the discount percentage from an original and sale price — instantly, no button needed.
Add tax?
Applied on top of the discounted price.
Final price
—.—
You saved —.—
Results update as you type.
What is a discount?
A discount is a reduction in the original price of a product or service. The two most common types are percentage discounts (e.g. 20% off) and fixed amount discounts (e.g. 20 off).
This calculator handles both, plus it can work backwards — give it the sale price and the discount, and it tells you the original price.
How to calculate a discount
Final price
original × (1 − discount %)e.g. 120 at 25% off = 90
Amount saved
original × discount %e.g. 120 at 25% off = 30
Final price + tax
(original × (1 − discount %)) × (1 + tax %)e.g. 90 + 8.1% tax = 97.29
Discount %
(original − sale) ÷ original × 100e.g. 120 → 90 = 25%
Worked examples
15% off 80
80 × 0.15 = 12 (discount amount)
80 − 12 = 68 (final price)
25% off 120 with 8.1% tax on top
120 × 0.25 = 30 (you save 30)
120 − 30 = 90 (after discount)
90 × 1.081 = 97.29 (final price with tax)
Find discount % — was 120, now 90
(120 − 90) ÷ 120 × 100 = 25% off
Need to calculate a percentage instead?
The Percentage Calculator handles percentage of a value, percentage difference, and percentage change — fast and simple.
Frequently asked questions
How do I calculate 20% off a price?
Multiply the original price by 0.20 to get the discount amount, then subtract from the original price. For example, 20% off 100 = 20 saved, final price 80.
How do I add tax to a discounted price?
Apply the discount first, then multiply by (1 + tax rate). For 25% off 120 with 8.1% tax: (120 × 0.75) × 1.081 = 97.29. Toggle 'Add tax' on the Final price tab to do this in one step.
How do I calculate the discount percentage?
Subtract the sale price from the original, divide by the original, and multiply by 100. Example: (120 − 90) ÷ 120 × 100 = 25%.
What is the difference between percent off and fixed amount off?
Percent off removes a percentage of the original price. Fixed amount removes a specific currency value regardless of the original price.
What if there are multiple discounts (stackable)?
Apply them sequentially. A second discount is applied to the already-reduced price, not the original. Use the calculator twice — first for the initial discount, then for the second.
Can I use this for coupons?
Yes. Enter the original price and the coupon percentage or fixed amount to see the final price and savings instantly.
Does this work for any currency?
Yes. The calculator is currency-neutral — enter any number and the formulas work the same regardless of the currency symbol.
Should I use this for Swiss pricing?
Yes. The calculator rounds to two decimal places, matching centime-level precision for CHF pricing.