Skip to content
Utilboxes

Discount Calculator

Find the sale price and what you saved, stack multiple discounts, or work backwards from a sale price to the original.

Runs entirely in your browser

How to use the Discount Calculator

  1. 1Choose a mode: a single discount, several stacked discounts, or working backwards from a sale price.
  2. 2Enter the price and the percentage off.
  3. 3Read the final price, the amount saved, and the effective discount.
  4. 4Add a tax rate if you want to see the price you actually pay at the till.

How it works

A single discount multiplies the price by one minus the rate. Stacked discounts are the part people get wrong: 20% off then a further 10% off is not 30% off. The second discount applies to the already-reduced price, so the true saving is 28%.

Working backwards divides rather than multiplies. If an item is 45 after 25% off, the original was 45 ÷ 0.75 = 60.

Where tax is involved, order matters in principle but not in arithmetic: applying a discount and then tax gives the same total as tax then discount, because both are multiplications. The tool applies the discount first, which is how most retailers present it.

The formula

sale price = original × (1 − d) stacked = original × (1 − d₁) × (1 − d₂) original = sale ÷ (1 − d)
original
the pre-discount price
d
the discount as a decimal, e.g. 0.25 for 25%
d₁, d₂
successive discounts applied one after another

Worked example

A 120 coat with 30% off, plus an extra 15% member discount

  1. 120 × 0.70 = 84
  2. 84 × 0.85 = 71.40

Result: 71.40 to pay — a saving of 48.60, an effective discount of 40.5%, not 45%.

Frequently asked questions

Do stacked discounts add together?
No. Each applies to the price after the previous one. 20% then 10% gives a 28% total saving, not 30%.
How do I find the original price from a sale price?
Use the reverse mode. It divides the sale price by one minus the discount — 45 at 25% off means the original was 60.
Should tax be applied before or after the discount?
The total is the same either way, since both are multiplications. Retailers normally discount first and then tax the reduced price.

Related tools

Percentage CalculatorWork out percentages, increases, decreases and 'what percent of'.Tax CalculatorAdd or remove sales tax, VAT or GST from any amount.Currency ConverterConvert between 30+ currencies using daily reference rates.ConvertersSalary CalculatorConvert between hourly, weekly, monthly and yearly pay.