How to use the discount calculator
- Enter the original price of the item.
- Enter the discount percentage or drag the slider.
- Optionally add an extra discount (applied after the first) and sales tax.
- Read the final price, how much you save and the effective discount.
Formula
Know the real price before you buy
“Up to 40% off”, “extra 15% at checkout”, “plus tax” — sale pricing is designed to be hard to do in your head. This calculator turns any combination into one clear number: what you’ll actually pay.
How the discount is calculated
A percentage discount scales the price down:
Sale price = Original price × (1 − discount ÷ 100)
For 25% off $120, the sale price is 120 × 0.75 = $90, so you save $30.
Stacked discounts
When a second discount is applied on top of the first, it works on the already-reduced price:
| Step | Price |
|---|---|
| Original | $120.00 |
| 25% off | $90.00 |
| Extra 10% off | $81.00 |
The total saving is $39, an effective discount of 32.5%, not 35%. The calculator shows this effective figure so you can compare “25% + 10%” deals against a flat 30% or 35% offer.
Adding sales tax
Tax is applied to the discounted price. At 8% tax, the $81.00 item above costs $87.48 at the register.
Shopping tips
- Compare effective discounts, not headline numbers. Two stacked discounts are always worth less than their sum.
- Watch the base price. A big percentage off an inflated “original” price may not be a deal. Check what the item usually sells for.
- Percent off vs. amount off. A “$20 off $100” coupon is a 20% discount; on a $60 item it’s worth 33%. Use the percentage calculator to convert between them.
Frequently asked questions
How do I calculate a discount?
Multiply the original price by the discount percentage divided by 100 to get the amount saved, then subtract it from the original price. For 20% off $50, you save $10 and pay $40.
Is 20% off and then 10% off the same as 30% off?
No. Stacked discounts multiply, not add. 20% then 10% off is 0.8 × 0.9 = 0.72 of the price, an effective 28% discount rather than 30%.
Is sales tax applied before or after the discount?
In most places sales tax is charged on the discounted price, which is what this calculator does.
Can I use decimals?
Yes. Prices and percentages accept decimals, such as 12.5% off $79.99.