Invoice VAT Calculator

How Do You Calculate VAT Across Multiple Invoice Lines?

Enter one item or service on each line, including its quantity, unit price, discount, and VAT rate. Choose net prices to add tax or gross prices to extract the included tax. Read the grouped totals and compare both rounding methods before copying the spreadsheet table or downloading the CSV worksheet. Everything in the calculation runs in your browser.

The starting amount for a line is quantity multiplied by unit price. A discount reduces that amount before tax: two units at 50 with a 10% discount produce a discounted amount of 90. When prices are net and VAT is 20%, the unrounded tax is 18 and the gross charge is 108. A discount of 100% removes the full charge, while a quantity of zero also produces a zero line.

For a complete mixed-rate example, select Net (excluding VAT), EUR, and Per line. Enter the three lines below. The first line has quantity 2, unit price 100, discount 10%, and VAT 20%; the other two have quantity 1, unit price 100, and no discount. Their VAT rates are 5% and 0%. Both rounding methods give the same totals here because none of the calculated amounts contains a fraction of a cent.

Mixed-rate invoice with a discount applied before VAT, in EUR

Line	Discounted net	VAT rate	VAT	Gross
Two units with 10% discount	180.00	20%	36.00	216.00
One reduced-rate item	100.00	5%	5.00	105.00
One zero-rate item	100.00	0%	0.00	100.00
Total	380.00	Mixed	41.00	421.00

The discounted first line follows 2 × 100 × (1 − 10 ÷ 100) = 180. Its VAT is 180 × 20 ÷ 100 = 36. The rate summary lists the groups in ascending order, so the zero-rate group appears before 5% and 20%, regardless of the order in which you entered those lines.

Why Can Line Rounding Differ From Invoice Rounding?

The difference comes from the order of operations. Per-line mode rounds each discounted net amount and its tax to two decimals, then adds those rounded amounts. In gross mode, it rounds the discounted gross amount and tax, with net calculated as gross minus tax. This keeps the displayed net plus VAT equal to gross. Half-up rounding means an exact amount of 1.005 rounds to 1.01.

Invoice-total mode keeps the discounted amounts and tax as exact fractions until the lines have been grouped by VAT rate. It then rounds the amount and tax once for each group. Two net amounts of 0.03 at 20% produce a tax total of 0.02 with line rounding but 0.01 with invoice rounding. Neither setting changes your input values. The comparison panel reports invoice rounding minus line rounding, so a negative VAT difference means invoice rounding produced less tax.

There is no single setting here that establishes compliance for every invoice. This tool exposes the arithmetic so you can reconcile a document using its chosen method. When checking a supplier invoice, compare the net, VAT, and gross differences separately. Gross-inclusive entries can keep the same payable total while shifting one cent between net and VAT, which is why comparing only the final payment can hide a mismatch.

How Are Mixed Rates and Gross Prices Kept Separate?

An invoice containing several rates must preserve those rate groups during calculation. For example, a net line of 100 at 20% creates 20 tax, while another net line of 100 at 5% creates 5 tax. Their combined gross total is 225. Applying either rate to the combined net amount would change the answer. The rate summary shows each group's net, VAT, and gross alongside the grand total.

Gross entry reverses the tax calculation rather than subtracting a percentage of the gross price. A gross amount of 120 at 20% contains 100 net and 20 tax. Subtracting 20% of 120 would remove 24 and incorrectly leave 96. The global Prices entered setting applies to every line, so normalize a worksheet that mixes net and gross quotations before entering it. A zero rate gives equal net and gross amounts with no tax.

For net entries, VAT = discounted amount × rate ÷ 100. For gross entries, VAT = discounted amount × rate ÷ (100 + rate). A gross unit price of 120 with quantity 1, discount 10%, and VAT 20% first becomes 108 gross, then separates into 90 net and 18 VAT. Changing Prices entered reinterprets the existing numbers; it does not convert the unit prices for you.

The VAT rate menu offers 0%, 5%, 5.5%, 7%, 9%, 10%, 19%, 20%, 21%, 23%, and 25%, plus Custom. These are numerical choices rather than country rules. Equivalent custom entries such as 5.5 and 5.5000 share one rate group. Select the rate appropriate to the supply yourself; the calculator does not identify a product's tax treatment from its description.

What Does the Spreadsheet Export Include?

Copy as table produces tab-separated text for spreadsheets. Download CSV includes the same calculation context: currency code, input direction, rounding mode, line descriptions and values, grouped rate totals, and the grand total. Line amounts in the export always show per-line rounding; in invoice mode, the grouped totals are authoritative and may differ from the sum of those displayed line amounts. The export includes a reminder of that distinction.

Descriptions that begin like spreadsheet formulas receive a protective prefix, and fields containing separators or newlines are quoted. Currency selection formats values without performing an exchange conversion. Inputs accept non-negative decimal values with up to four decimal places and support up to 100 lines. This worksheet does not handle reverse charge, tax exemptions as legal categories, credit notes, or tax-return preparation. For one amount use the VAT Calculator; check a reduction separately with the Discount Calculator.

What Should You Check When an Invoice Does Not Match?

First confirm whether the source prices exclude or include VAT, then compare quantity, discount, and rate on each line. A discount belongs to its own line: there is no separate invoice-wide discount field. If a reduction applies across an entire invoice, allocate it to the relevant lines before entering the figures. Keep different rates separate rather than replacing them with an average percentage.

Next compare both columns in Rounding comparison. For two gross lines of 0.03 at 20%, per-line rounding gives 0.04 net, 0.02 VAT, and 0.06 gross. Invoice rounding gives 0.05 net, 0.01 VAT, and the same 0.06 gross. The difference is therefore +1 cent net, −1 cent VAT, and zero gross. This distinguishes a tax allocation difference from a different amount payable.

What Input Limits and Currency Options Apply?

The worksheet supports 1 to 100 invoice lines. Each quantity can be at most 10,000, each unit price at most 1,000,000, and both discount and VAT rate at most 100%. All numeric fields accept non-negative values with up to four decimal places. Use a decimal dot, such as 12.3456; grouped numbers such as 1,000, scientific notation such as 1e2, negative values, and blank numeric fields fail validation. An invalid line hides the results until corrected.

A new line starts with quantity 1, unit price 0, discount 0%, and VAT 20%. Description is optional and limited to 500 characters in the editor. Add line becomes unavailable at 100 lines, and Remove line cannot remove the last remaining line. These limits make zero-value test lines possible without requiring a description or a positive charge.

Currency offers EUR, GBP, USD, CAD, AUD, CHF, and TRY, with EUR initially selected. All calculation amounts round to two decimal places. Changing Currency does not change any quantity, price, or tax calculation, and there is no exchange-rate lookup. Enter all lines in one currency before using the totals. The CSV is a calculation worksheet rather than an invoice document with customer details, numbering, or payment terms.