Discount Calculator
Enter the original price, the discount percentage and any extra discount or fixed coupon to see the final price, the total saving and the true combined rate.
Worked example: 20% off, then a further 10% off
| Step | Calculation |
|---|---|
| Original price | 200 |
| After the 20% discount | 200 × 0.80 = 160 |
| After the additional 10% discount | 160 × 0.90 = 144 |
| Effective total discount | (200 − 144) ÷ 200 = 28% |
How to use
- Enter the original price of the item.
- Add the main discount, and optionally a second stacked discount and a fixed coupon amount.
- Click Calculate to see the final price, the total saving and the effective discount percentage.
Frequently asked questions
Do a 20% and a 10% discount add up to 30% off?
No, and this is the most common mistake with stacked offers. The second percentage is taken from the already-reduced price, not from the original one. On 200, taking 20% off gives 160, and a further 10% off gives 144 — an effective discount of 28%, not 30%. The calculator shows this effective percentage so you can compare offers fairly.
In what order are the discounts and the coupon applied?
Percentage discounts are applied one after another, and the fixed coupon amount is subtracted from the price that remains. The order of the two percentage discounts does not change the result, because multiplying by both factors gives the same figure either way. Subtracting the coupon last matches how most shops apply codes at checkout, where the percentage discount is taken before the voucher value.
Why is the effective discount never as high as the percentages suggest?
Because each percentage acts on a shrinking base. After the first discount removes its share, the second percentage is calculated on a smaller amount, so it contributes less than its face value. Only a single discount equals its own percentage; every additional stacked discount loses a little to the smaller base it lands on. The effective figure is always the honest number.
Can I use it for tax, fees or buy-one-get-one offers?
The tool models percentage discounts and one fixed coupon amount only. It does not add or remove sales tax, and it cannot express complex offers such as buy-one-get-one or tiered pricing. For such cases, work out what the offer effectively costs per item and treat that as your starting point before comparing percentage discounts here.
Are the results exact?
The calculations are exact arithmetic for the numbers you enter — no rounding is hidden inside the steps. What the tool cannot know is the store’s own rules: some shops round each discount separately, apply coupons before percentages, or exclude certain items from promotions. Treat the output as a precise estimate of a well-defined scenario, not a guarantee of the checkout total.