Add your line items, apply discount and tax, and get an instant invoice total.
| Description | Qty | Rate | Line Total |
|---|
Add a line item for each product or service, entering a description, quantity, and rate per unit — the line total calculates automatically. Add as many line items as needed, then enter any overall discount percentage and the applicable tax rate. The calculator totals everything into a subtotal, discount amount, tax amount, and final total due.
This calculator applies the discount to the subtotal first, then calculates tax on the discounted amount — which matches standard invoicing practice in most jurisdictions and most accounting software. Calculating tax before discount would result in the customer being taxed on an amount they're not actually paying.
Clear, itemised line items make it easy for a client to see exactly what they're being charged for, which reduces back-and-forth questions and payment delays. Keeping descriptions specific (a service and the time period, or a product and the quantity) is generally more effective than a single lump-sum line.
Tax should be calculated after the discount is applied, on the discounted subtotal. This is standard practice because the discount reduces what the customer actually owes, and tax should reflect the real amount being paid, not the original undiscounted price.
This depends on your location and the type of goods or services — for example, GST is commonly 15% in New Zealand and 10% in Australia, while VAT and sales tax rates vary by country and sometimes by region or product category. Check your local tax authority's current rate, since this calculator simply applies whatever percentage you enter.
Yes — the calculation is identical whether you're preparing a quote for a prospective job or an invoice for completed work. The only difference is typically the heading and payment terms on the document you actually send to the client.