How do I calculate a discount?

Multiply the original price by (1 − discount percentage ÷ 100). For example, a 20% discount on $100: $100 × (1 − 0.20) = $80. The savings are $20.

Why are two discounts not simply added together?

Percentage discounts are applied sequentially, not additively. A 20% discount followed by a 10% discount means the second 10% is applied to the already-reduced price of $80, giving $72 — not a 30% discount of $70. The effective discount is 28%.

What is the effective discount?

The effective discount is the total savings divided by the original price, expressed as a percentage. It captures the combined effect of multiple discounts and fixed coupons in a single number.

Can the final price go below zero?

No. This calculator ensures the final price never falls below zero, even if a fixed coupon exceeds the discounted price.

Discount Calculator

Q: Does this calculator store my data?

No. All calculations run locally in your browser. Your figures are not sent to a server or stored by us.

Work out the final price after one or two percentage discounts plus a fixed coupon, see your total savings, and understand the effective discount when offers are stacked sequentially.

Last reviewed: 2026-07-29

Discount Calculator inputs

Fill in the fields below, then select Calculate. Nothing is submitted automatically.

Original Price

The full price before any discount.

First Discount %

The main percentage discount.

Additional Discount % (optional)

A second percentage applied to the already discounted price.

Fixed Coupon Amount (optional)

A fixed dollar amount subtracted after percentage discounts.

Quantity (optional)

Number of units. Defaults to 1.

Currency

Changing the currency changes formatting only. It does not convert values between currencies.

Calculations run locally in your browser. Your figures are not sent to a server or stored by us.

Results

Enter your figures above and select Calculate. Results appear here with clear labels — never colour alone.

How to calculate a discount

A discount reduces the price of an item by a percentage or a fixed amount. To calculate the sale price, multiply the original price by one minus the discount rate. A 20% discount means you pay 80% of the original price.

When multiple discounts are stacked — for example a seasonal sale plus a loyalty coupon — each percentage is applied to the price after the previous discount, not to the original price. This is why two 20% discounts do not equal a 40% discount.

Discount formula

Price After First Discount = Original × (1 − First Discount ÷ 100)
Price After Second Discount = Price After First × (1 − Second Discount ÷ 100)
Final Unit Price = max(0, Price After Second − Coupon)
Savings per Unit = Original Price − Final Unit Price
Effective Discount = Savings ÷ Original Price × 100
Total Sale Price = Final Unit Price × Quantity

Worked example

An item costs $100. A 20% discount is applied, followed by an additional 10% discount, with no coupon and a quantity of 1.

After 20%: $100 × 0.80 = $80
After 10%: $80 × 0.90 = $72
Savings = $100 − $72 = $28
Effective Discount = $28 ÷ $100 × 100 = 28%

Notice that 20% + 10% = 30%, but the effective discount is only 28% because the second discount applies to a smaller base. See the percentage calculator for more on percentage calculations.

How to use this calculator

Enter the original price and the first discount percentage. Optionally add a second percentage discount, a fixed coupon amount, and a quantity. The calculator applies discounts in order: first percentage, second percentage, then fixed coupon — and never lets the price go below zero.

Interpreting the results

The effective discount percentage shows the true total savings relative to the original price. This is the number to compare when evaluating whether a stacked discount is better than a single larger discount.

The total sale price accounts for quantity, making it useful for bulk purchases or multi-item orders.

Common mistakes

Adding percentages. Two 20% discounts are not 40% off — they are applied sequentially.
Forgetting the coupon order. Fixed coupons are subtracted after percentage discounts, which changes the effective rate.
Ignoring quantity. The per-unit savings multiply across all units.
Confusing discount with tax. Discounts reduce price; taxes increase it. See the sales tax calculator.

Frequently asked questions

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Disclaimer

Results from this calculator are estimates for general information only and are not financial, accounting, tax, investment or legal advice. Verify important figures with a qualified professional. Read our full disclaimer.