How to Calculate VAT in the EU: Formulas, Reverse Math & Worked Examples (2026)

By CA Neha Tabassum, Chartered Accountant · Rates checked against the EU VAT rates table · Updated 5 October 2026

Every VAT calculation you will ever meet — in any of the 27 EU countries, at any rate — reduces to two formulas. Most invoicing errors come not from the rate but from applying the right percentage to the wrong base: adding 19% to a net figure works, subtracting 19% from the gross figure silently does not. This guide gives you both formulas, shows exactly why the naive reverse fails with real numbers, then works through every common case including mixed-rate invoices, rounding, and discounts.

1. The only two formulas you need

VAT is always computed on the net amount — the price before tax. Call the net N, the rate r (written as a decimal, so 19% is 0.19), the VAT amount V, and the gross G. Then:

Adding VAT:  V = N × r    G = N × (1 + r)
Removing VAT:  N = G ÷ (1 + r)    V = G − N

Two observations that save more money than any rate table. First, the rate never changes the procedure — Germany's 19%, Hungary's 27% and Luxembourg's 17% all run through the identical two lines; only r changes. Second, the remove formula is a division, not a subtraction, and that single fact is responsible for most of the real-world errors this guide corrects. If you take nothing else from this page, take the division.

A €100 net supply at 19% gives V = 100 × 0.19 = €19.00 and G = 100 × 1.19 = €119.00. The same €100 at 27% gives €27.00 and €127.00. Nothing else is ever happening underneath these two lines, no matter how complicated the invoice looks.

2. Why subtracting the percent from gross fails

Here is the most expensive three-second mistake in European invoicing. Presented with a gross of €119 at 19%, someone computes 119 − 19% = 119 × 0.81 = €96.39 and records €96.39 net with €22.61 VAT. Both numbers are wrong: the true net is €100.00 and the true VAT is €19.00.

Why? Because a percentage is always a percentage of something, and the two somethings differ. The €19 of VAT is 19% of the €100 net. But €19 is only about 15.97% of the €119 gross (19 ÷ 119 = 0.1597). Subtracting "19%" from the gross subtracts 19% of 119, which is €22.61 — €3.61 more than the actual VAT. Every gross figure on every invoice contains its VAT at a smaller percentage than the headline rate, which is exactly why the remove formula divides instead of subtracting.

The correct reverse: N = 119 ÷ 1.19 = €100.00, V = 119 − 100 = €19.00. Run it on the VAT calculator in Remove mode if you want to watch the division happen — and notice the calculator never offers a "subtract percent" button, because no correct procedure looks like that.

3. Worked examples at real EU rates

Same procedure, six different countries. Each line shows the full arithmetic so you can check it with a pocket calculator:

Notice how the procedure never varies: multiply by the rate for the tax, multiply by one-plus-the-rate for the total. The country pages carry each member state's full rate structure if you need reduced rates too — see the EU VAT rates table for all 27.

4. Reverse calculations, worked

Going backwards — gross to net — is where the division earns its keep. Two full examples:

The check step is not decoration. Every reverse calculation should be re-multiplied forward: if N × r does not reproduce V to the cent, either the rate is wrong or the gross was rounded upstream — both worth knowing before the invoice goes out rather than during an audit.

5. Mixed-rate invoices and per-rate subtotals

A French restaurant bill is the classic case: food at 10%, wine at 20%. Article 226(8) of the VAT Directive requires the taxable amount per rate — one blended line at an average rate fails, because no single rate was actually applied to anything. Take €100 of food at 10% and €50 of wine at 20%:

• Food: VAT = 100 × 0.10 = €10.00, gross €110.00
• Wine: VAT = 50 × 0.20 = €10.00, gross €60.00
• Document totals: net €150.00, VAT €20.00, gross €170.00

Each rate gets its own subtotal line showing net and tax, then one gross total for the document. Our invoice generator builds these subtotals automatically — one line per rate, exactly as Article 226(8) requires. For the full field list behind compliant invoices, see the EU invoice requirements guide.

6. Rounding rules and the one-cent difference

Money stops at cents; percentages do not. The convention is round half up to the nearest cent, applied consistently within a document. Inconsistency, not rounding itself, is what creates real discrepancies: rounding each line separately versus rounding the document total can differ by a cent, and both answers are defensible as long as the method does not change mid-invoice.

Concrete case. Three lines of €14.99 net at 19%: per line, 14.99 × 0.19 = 2.8481, which rounds to €2.85 — three lines give €8.55 of VAT. On the document total instead: 44.97 × 0.19 = 8.5443, which rounds to €8.54. Same invoice, one cent apart, both correctly computed. Tax authorities accept either treatment applied consistently; what they question is a document that mixes the two, because then the totals cannot be reconstructed from the lines.

7. Discounts apply before VAT

VAT is charged on what the customer actually pays, so any discount comes off first and the tax applies to the reduced net. A €200 item with 10% off, taxed at 20%: net becomes 200 × 0.90 = €180.00, VAT is 180 × 0.20 = €36.00, gross is €216.00. Computing VAT first (200 × 1.20 = 240) and then discounting gives €216.00 as well here — but only because a single flat discount commutes with a single rate; with stacked or conditional discounts the order matters and discount-first is the only correct sequence. The full treatment, including why 25% plus 10% is 32.5% and not 35%, is in Sequential vs Stacked Discounts.

8. Mental-math shortcuts that stay exact

Not every calculation needs a calculator if the shortcut is algebraically identical to the formula rather than an approximation. Three that always hold. First, build 20% as twice 10%: move the decimal point one place for 10%, then double. A €250 net supply at 20% gives 10% = €25.00, doubled to €50.00 VAT, gross €300.00 — exactly the table figure from section 3. Second, 25% is one quarter on top: divide the net by four and add it. An €80 net supply at 25% gives 80 ÷ 4 = €20.00, gross €100.00. Third, reversing 20% without dividing by 1.2: since 1 ÷ 1.2 = 5/6, the net is the gross minus one-sixth of itself. A €300 gross at 20% gives 300 ÷ 6 = €50.00 off, net €250.00 — again exactly the table figure. Each shortcut is the formula rearranged, not rounded, so nothing is lost; use them for quotes on the phone and the calculator for invoices.

9. Refunds, credit notes, and price cuts

A returned good un-does the original calculation: where the price is reduced after the supply — a full return, a partial credit, a retrospective discount — Article 90 of the VAT Directive reduces the taxable amount accordingly, under conditions each Member State sets itself. The mechanism is a credit note referencing the original invoice, never an edited invoice. Take the Italian row from the table above: €200 net at 22%, gross €244. A full return means a credit note for the whole €244, reversing €44 of VAT. A return of half the goods (€100 net) means a credit note for 100 × 1.22 = €122.00, reversing €22.00 of VAT. The arithmetic is the forward formula run in reverse on the returned portion only; the kept portion is untouched. Businesses that refund often should agree the credit-note routine with their accountant once, because member states set their own documentary conditions and getting them wrong converts a clean reversal into an unrelieved assessment.

10. Which country's rate? The 30-second check

Knowing how to compute VAT is half the job; the other half is whose rate. Three questions settle the common cases. Selling goods to a consumer in another EU country? Destination country's rate applies once pan-EU cross-border turnover passes €10,000 a year — below that, your home rate may apply. Supplying B2B services across a border? The customer's country generally taxes it and the reverse charge moves the liability to them; run the reverse charge versus OSS checker before invoicing, and read the reverse charge liability rules for which article fires. Moving your own goods between member states for a VAT-registered customer? Zero-rated dispatch under the intra-Community supply rules, with both VAT numbers on the invoice and the EC Sales List filed. If none of those three patterns matches — digital services to consumers, triangulation chains, goods installed on site — stop and look it up rather than guessing, because those are the cases with their own dedicated rules. The rates table then supplies the number once the country is settled.

11. The mistakes that cost money

1. Subtracting the rate from the gross. €119 minus "19%" gives €96.39, not €100. Divide by 1.19 instead — every time, without exception.
2. One blended line for mixed rates. Averaging 10% and 20% into 15% applies a rate that exists nowhere in law. Subtotal per rate.
3. Taxing the pre-discount price. VAT follows what the customer pays. Discount first, then tax — particularly with stacked discounts where the sequences diverge.
4. Mixing rounding methods in one document. Per-line on some lines, per-total on others. The totals stop reconstructing from the lines, which is exactly what an auditor checks first.
5. Forgetting the reverse check. Every gross-to-net computation should be re-multiplied forward. A ten-second check catches wrong-rate and rounded-gross errors before issue.
6. Using last year's rate from memory. Finland moved 24% to 25.5%, Estonia 22% to 24%, Romania 19% to 21% — all within the last two years. Check the current table, not your habits.

Frequently asked questions

Sources

• Article 226(8) of Council Directive 2006/112/EC (consolidated) — taxable amount per rate, unit price exclusive of VAT, discounts and rebates
• VAT rates — European Commission, consulted October 2026 (standard rates used in the worked examples)

Verification status: every figure in the worked examples was computed by hand and cross-checked on 5 October 2026; the standard rates match the country pages and master table as published. The Article 226(8) requirement was read verbatim from the consolidated Directive. Corrections are logged in the changelog.