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Discount Rate Calculator

The discount rate is the percentage applied when a product or service is offered below its list price. It is calculated with the following formula.

Discount Rate

Discount Rate Calculation Method

To calculate the discount rate, first subtract the sale price from the list price to find the actual discount. Then divide this discount by the list price to get its proportion of the list price. Finally, multiply this ratio by 100 to convert it to a percentage — that percentage is the discount rate.

Discount rate = \left( (List price - Discounted price)/(List price) \right) × 100

For example, if a product with a list price of $100 is sold for $80, the discount rate is calculated as follows:

\left( (100,000 - 80,000)/(100,000) \right) × 100 = 20\%
The discount rate is 0 %.

About This Calculator

A discount rate is the percentage taken off a list price. Shops advertise discounts, but comparing a "30% off" offer with a "buy two, get one free" deal usually needs the effective percentage, which is what this calculator gives you.

Enter the original price and the sale price to get the discount amount and the discount rate.

A discount applies to the original price, so stacking two discounts is not the same as adding them: 20 % then a further 10 % gives 28 % off in total, not 30 %. On a 100 item the final price is 72 rather than 70. Working backwards needs care as well — recovering the original price from a sale price means dividing by (1 − rate).

Key Formula:Discount rate (%) = (Original − Sale) / Original × 100

Frequently Asked Questions

How do I calculate the final price after a discount?

Multiply the original price by one minus the rate: a 30% discount off $80 is 80 × 0.7 = $56. Adding VAT therefore comes after the discount is applied, not before.

Are stacked discounts added together?

No — they compound on the already-reduced price. "Extra 20% off sale prices" after a 30% discount is 1 − (0.7 × 0.8) = 44% off, not 50% off.

Is 30 % off the same as 30 % extra product free?

No. Taking 30 % off leaves a price of 70 for the same quantity, which is 0.70 per unit. Getting 130 units for the price of 100 is 0.77 per unit, so the discount is the better deal for the buyer.

How do I find the original price after a discount?

Divide the sale price by (1 − rate). If 80 is the price after 20 % off, the original was 80 / 0.8 = 100. Adding 20 % back to 80 would give 96, which is wrong.

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Sources & last update

2026-10-19