VAT Calculator guide
Use this calculator when a price is either before VAT (net) or already includes VAT (gross) and you want to find the tax amount and the corresponding other price. The direction matters: adding VAT to a net price and extracting VAT from a gross price are inverse calculations, not the same percentage operation.
The calculator applies the VAT rate you enter. It does not decide which rate, exemption, place-of-supply rule, registration rule, or invoice treatment applies to a transaction; those depend on the relevant tax authority and the goods, services, parties, and jurisdiction involved.
How the calculation works.
Gross = Net × (1 + r); Net = Gross ÷ (1 + r); VAT = Gross − Net- Net = price before VAT
- Gross = price including VAT
- r = VAT rate written as a decimal, so 20% becomes 0.20
- VAT = tax amount contained in or added to the price
Follow the numbers in context.
Add 20% VAT to a €100 net price
Convert 20% to 0.20. Gross = €100 × 1.20 = €120. The VAT amount is €120 − €100 = €20. Here €100 is the tax base, so 20% of the net amount is the tax added.
Remove 20% VAT from a €120 gross price
Do not subtract 20% of €120. Divide instead: Net = €120 ÷ 1.20 = €100, and VAT = €120 − €100 = €20. Subtracting 20% of the gross price would give €96 because it uses the wrong base.
Use the number for the question this tool answers.
When adding VAT, the VAT percentage is applied to the net price. When removing VAT, the gross price already contains both net and tax, so dividing by 1 + rate recovers the original tax base.
A useful check is to recombine the result: net + VAT should equal gross. If it does not, first verify the direction, rate, and whether the starting price was VAT-inclusive.
More detail: inputs, assumptions, mistakes and edge cases
Build a dependable estimate.
- Choose the direction that matches the number you actually know: add VAT when your starting amount is net; remove VAT when your starting amount already includes VAT.
- Enter the monetary amount and the applicable VAT rate as a percentage, such as 21 for 21%. Do not enter 0.21 unless the input explicitly asks for a decimal rate.
- Read the net, VAT, and gross amounts together. Their relationship should always satisfy net + VAT = gross, apart from any displayed currency rounding.
- For invoices containing items at different VAT rates, calculate each rate group separately rather than applying one blended rate to the entire invoice unless your accounting rules specifically permit that treatment.
Keep measurements compatible.
Net, VAT, and gross amounts must all use the same currency. The percentage is a rate, not a currency conversion. If an invoice uses another currency, perform any required exchange-rate treatment separately under the applicable tax rules.
Know what the result includes.
Assumptions
- The entered rate applies to the full entered tax base in a single VAT calculation.
- The gross price is modeled as net price plus VAT calculated on that net price.
- The tool uses mathematical percentage calculations and does not apply jurisdiction-specific invoice rounding, exemptions, reduced-rate eligibility, reverse charge, or special VAT schemes.
Limitations
- This is an arithmetic aid, not tax advice. VAT rates and rules can change, and the correct treatment can depend on location, customer type, product or service classification, registration status, and transaction date. Confirm the applicable rate and treatment with the relevant tax authority or a qualified adviser.
- Real invoices can round tax per line, per rate group, or at invoice total depending on local rules and accounting software. Small differences of the smallest currency unit can therefore occur even when the underlying rate is the same.
Avoid preventable errors.
- Do not remove VAT by subtracting the VAT percentage from a VAT-inclusive price. At 20%, €120 gross contains €20 VAT; subtracting 20% of €120 would incorrectly produce €96.
- Do not assume a country’s standard VAT rate applies to every sale. Reduced rates, zero rates, exemptions, reverse-charge rules, and cross-border rules can change the treatment.
- Do not mix net and gross prices when comparing suppliers. Confirm whether each quoted amount includes VAT before comparing totals.
- Do not treat VAT collected as ordinary sales revenue when doing business-profit calculations; accounting and remittance treatment should follow the applicable rules.
Check unusual inputs carefully.
At a 0% entered rate, net and gross are equal and the calculated VAT amount is zero. A zero-rate transaction can still have reporting requirements that this calculator does not determine.
A negative amount can arise in credit notes or adjustments, but the correct VAT documentation and sign convention depend on the accounting context.
If a gross total combines multiple VAT rates, one reverse calculation cannot reliably recover each underlying net amount without knowing how the total was split.
Questions about this calculation.
How do I add VAT to a net price?
Convert the VAT percentage to a decimal and multiply the net price by 1 plus that rate. At 20%, €100 net × 1.20 = €120 gross, containing €20 VAT.
How do I remove VAT from a gross price?
Divide the VAT-inclusive price by 1 plus the VAT rate as a decimal. At 20%, €120 ÷ 1.20 = €100 net; the remaining €20 is VAT.
Why can’t I subtract 20% to remove 20% VAT?
Because the 20% VAT was calculated from the smaller net price, not from the larger gross price. The inverse of multiplying by 1.20 is dividing by 1.20.
Does this calculator know the correct VAT rate for my country or product?
No. You supply the rate. Verify the current rate and transaction treatment with the relevant tax authority because standard, reduced, zero, exempt, and special treatments differ.
Why can my invoice differ by a cent from the calculator?
Invoice systems and tax rules may round at line, rate-group, or invoice level. Those rounding sequences can create a small difference from a single calculation on the final total.
Can I use one calculation for an invoice with several VAT rates?
Only if you already have a valid combined tax basis for that purpose. Normally, calculate each VAT-rate group separately so the tax base and tax amount remain traceable.