How do percentage and fixed discounts combine?

Both come off the original price: the percentage is worked out on the original price, not on the price after the fixed discount, and the two are added. The combined discount can't be more than the original price, so the sale price never goes below $0.00.

What is the effective discount?

The total discount divided by the original price, as a percentage, rounded to one decimal place. On a $100.00 item, 10% off plus $5.00 off saves $15.00, an effective discount of 15.0%.

How is the discount rounded?

The percentage discount is rounded to the nearest cent, with half a cent or more rounding up. 15% of $19.99 is $2.9985, so the discount is $3.00 and the sale price is $16.99.

What if my offer takes one discount after the other?

Then the second discount applies to the reduced price. Work out the first discount here, enter the sale price as the new original price, and apply the second. For example, 10% off $100.00 gives $90.00, and a further 10% off gives $81.00, not $80.00.

Discount Calculator

Enter the original price, a percent off, a fixed amount off, or both, to see the sale price, how much is saved and the effective discount, rounded to the cent.

Price and discount

Enter a percentage discount, a fixed amount, or both. Both come off the original price, and together they can't be more than it.

Original price ($)

Discount (%)

Fixed discount ($)

An empty discount counts as 0. Prices and the fixed discount are entered to the cent.

Sale price

$170.00

You save $30.00 (15.0% of the original price).

Breakdown

Original price: $200.00
Discount (15%): −$30.00
Fixed discount: −$0.00
Total discount: −$30.00
Effective discount: 15.0%
Sale price: $170.00

Percentage discount = original price × discount rate, rounded to the nearest cent, half a cent rounding up. Sale price = original price − total discount. Effective discount = total discount ÷ original price, to one decimal place.

How the discount is calculated

The OpenStax Contemporary Mathematics textbook (section 6.2) gives the formulas, with the percent discount written as a decimal (15% = 0.15):

Discount = percent discount × original price

Sale price = original price − discount = original price × (1 − percent discount)

The calculator adds any fixed discount to the percentage discount, takes the total off the original price, and limits it to the original price. The effective discount is the total discount ÷ the original price, shown as a percentage to one decimal place.

The percentage discount is rounded to the nearest cent. OpenStax gives the half-penny rule for sales tax ("round up for half a penny or more, but round down for less than half a penny"), and the calculator applies the same rule to the discount.

Worked examples

The starting values: 15% off $200.00 is $200.00 × 0.15 = $30.00, so the sale price is $170.00, an effective discount of 15.0%.
Both discounts: 10% off $100.00 is $10.00; with $5.00 off as well, the total discount is $15.00 and the sale price is $85.00, an effective discount of 15.0%.
Rounding: 15% off $19.99 is $2.9985, which rounds up to $3.00, so the sale price is $16.99.

What you can enter

An original price and a fixed discount up to $1,000,000,000,000, to the cent.
A percentage discount from 0% to 100%, with up to 4 decimal places. An empty discount counts as 0.
No negative numbers.

To apply a discount across several line items with tax, use the invoice total calculator. To check what a discount leaves you after costs, use the markup calculator and the profit margin calculator. For how to show a discount on an invoice, see our guide to invoice discounts.

Frequently Asked Questions

Give discounts on your invoices

In Billed you can discount an invoice for a client or create coupons, and Billed calculates taxes from the tax rates and settings you save.

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