How do I calculate an invoice discount?

For a percentage discount, multiply the original amount by the discount rate. For a fixed discount, use the dollar amount you enter. Subtract the discount from the original amount to get the subtotal after discount.

What is the difference between a percentage and a fixed discount?

A percentage discount scales with the invoice amount (for example, 10% of $1,000 is $100). A fixed discount is a set amount (for example, $50 off), which this calculator also converts to an effective percentage.

How do I calculate the final invoice total after a discount?

Subtract the discount from the original amount, then add tax on the discounted subtotal if a tax rate is entered. For $1,000 with 10% off and no tax, the total is $900.

How do I calculate the effective discount percentage?

Divide the discount amount by the original invoice amount and multiply by 100. A $50 discount on $1,000 is a 5% effective discount.

Is tax calculated before or after the discount?

This calculator applies tax after the discount, on the discounted subtotal. Tax treatment can vary by jurisdiction, so confirm the rules that apply before you bill a customer.

How is this different from an early payment discount?

A general invoice discount reduces the amount due regardless of when the customer pays. An early payment discount (such as 2/10 Net 30) only applies if payment arrives by a stated deadline.

Invoice Discount Calculator

Apply a percentage or fixed discount to an invoice amount and see the savings, optional tax after the discount, and final total.

Currency

Used for display and invoice prefill. Amounts are not converted between currencies.

Original invoice amount

Discount type

Discount value

Enter a percentage from 0 to 100, or switch to a fixed amount.

Tax rate (optional)

Tax is calculated after the discount on the discounted subtotal. Leave blank or 0 to skip tax.

Discount summary

Final invoice total

$900.00

Original invoice amount: $1,000.00
Discount amount: $100.00
Subtotal after discount: $900.00
Tax amount: $0.00
Final invoice total: $900.00
Total savings: $100.00
Effective discount: 10%

Tax is applied after the discount on the discounted subtotal. Tax rules can vary by jurisdiction—this calculator does not choose a tax treatment for you.

Create an invoice with this discount

Ready to send it? Open the Invoice Generator or browse all calculators.

How to calculate an invoice discount

Choose a percentage or fixed discount, then subtract that discount from the original invoice amount. If you enter a tax rate, this calculator multiplies the discounted subtotal by the tax rate and adds the tax to get the final total.

Percentage vs. fixed discounts

A percentage discount scales with the invoice. A fixed discount is a set amount off. When you enter a fixed discount, the calculator also shows the equivalent effective percentage so you can compare the two approaches.

Worked example

Percentage discount

$1,000 × 10% = $100 discount → $900 subtotal → $900 final total with no tax.

Fixed discount

$50 off $1,000 → $950 subtotal. Effective discount = $50 ÷ $1,000 = 5%.

How to calculate the final invoice total after a discount

Final total = (Original amount − Discount) + Tax on the discounted subtotal.

With $1,000, 10% off, and 8% tax: discount $100, subtotal $900, tax $72, final total $972.

How to calculate the effective discount percentage

Effective discount % = Discount amount ÷ Original invoice amount × 100. A fixed $50 discount on $1,000 is 5%.

Invoice discount vs. early payment discount

A general invoice discount reduces what the customer owes on the document itself. An early payment discount only applies if the customer pays by a stated deadline (for example, 2/10 Net 30). Use the Early Payment Discount Calculator for deadline-based terms.

Tax after the discount

By default this calculator taxes the amount remaining after the discount. Some jurisdictions treat tax differently; verify the rules that apply to your invoices. Related tools: Sales Tax Calculator and VAT Calculator.

Build a full invoice total in the Invoice Calculator, price with the Markup Calculator or Margin Calculator, or open the Invoice Generator and browse All Calculators.

Frequently asked questions

How do I calculate an invoice discount?: For a percentage discount, multiply the original amount by the discount rate. For a fixed discount, use the dollar amount you enter. Subtract the discount from the original amount to get the subtotal after discount.
What is the difference between a percentage and a fixed discount?: A percentage discount scales with the invoice amount (for example, 10% of $1,000 is $100). A fixed discount is a set amount (for example, $50 off), which this calculator also converts to an effective percentage.
How do I calculate the final invoice total after a discount?: Subtract the discount from the original amount, then add tax on the discounted subtotal if a tax rate is entered. For $1,000 with 10% off and no tax, the total is $900.
How do I calculate the effective discount percentage?: Divide the discount amount by the original invoice amount and multiply by 100. A $50 discount on $1,000 is a 5% effective discount.
Is tax calculated before or after the discount?: This calculator applies tax after the discount, on the discounted subtotal. Tax treatment can vary by jurisdiction, so confirm the rules that apply before you bill a customer.
How is this different from an early payment discount?: A general invoice discount reduces the amount due regardless of when the customer pays. An early payment discount (such as 2/10 Net 30) only applies if payment arrives by a stated deadline.