Should tax be calculated before or after a discount?

It depends on jurisdiction and product type. Many businesses apply the discount to the subtotal first, then calculate tax on the reduced taxable amount. When in doubt, follow your accountant or local tax rules.

Can I use this for multiple tax rates?

This tool uses one blended tax rate on the post-discount subtotal. If you need multiple rates (e.g. services vs. goods), split line groups or use invoicing software that supports per-line tax.

How do discounts interact with line items?

Subtotal is the sum of quantity × unit price for all lines. Percentage discount applies to that subtotal; the fixed discount is added on top, and the combined discount cannot exceed the subtotal.

Invoice Total Calculator

Build line items, layer percentage and fixed discounts, and apply a single tax rate to see your invoice total and a clear breakdown.

Line items

Qty

Unit price ($)

Qty

Unit price ($)

Tax rate (%)

Discount (% of subtotal)

Additional discount ($)

Invoice total

$365.34

Subtotal $375.00 · Tax $27.84

Breakdown

Subtotal: $375.00
Discounts: −$37.50
After discount: $337.50
Tax (8.25%): $27.84
Total due: $365.34

How invoice totals are built

A professional invoice total is more than a single number: it shows clients how you arrived at the amount due. Start with line items—each row should reflect quantity and unit price so anyone can audit the math. The subtotal is the sum of those extended amounts (quantity times price). From there, discounts and taxes adjust what the customer pays, and the order of operations should match your policy and compliance requirements.

Percentage discounts reward larger purchases or early payment; fixed credits handle promotions or goodwill adjustments. Tax is often calculated on the taxable base after discounts, but rules vary. When you present a clean breakdown—subtotal, discounts, tax, and total—you reduce disputes and speed up approvals. For deeper pricing work, pair this with our profit margin calculator and sales tax calculator. Ready to send real invoices? See how to create a professional invoice in the Billed hub.

Frequently Asked Questions

Send invoices that match your math

Billed helps you create branded invoices, track payments, and keep client balances straight—so your totals in the app always match what you promised.

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