Using the UK VAT calculator correctly
Enter a net price and the VAT rate that applies to the supply. The calculator adds VAT to that net amount; it does not determine the correct VAT category for the goods or services.
Standard, reduced, zero-rated and exempt are different
HMRC lists a standard rate, a reduced rate and a zero rate. A zero-rated supply is still within the VAT system at 0%, while an exempt supply is treated differently. The default 20% is appropriate only when the standard rate applies. Some goods, services and circumstances use another treatment.
At 20%, a £80 net amount gives £16 VAT and a £96 gross total. If a price is already VAT-inclusive, adding 20% again is wrong. For a standard-rated inclusive total, the VAT component is normally the gross amount multiplied by 20/120, subject to the invoice's rounding method.
Checks before relying on an estimate
Confirm whether the quoted amount is net or gross, whether delivery or other charges follow the same VAT treatment, and which rate applies on the relevant tax point. Keep the supplier's invoice as the source of truth for an actual transaction.
HMRC says most goods and services use the standard rate, while reduced, zero-rated and exempt treatment applies in defined cases. Rates and temporary reliefs can change, so verify the current classification rather than relying on the example alone.
Frequently asked questions
Does 0% mean exempt?
No. Zero-rated and exempt supplies have different VAT consequences even though neither adds VAT to the customer price.
Can this calculator prepare a VAT return?
No. It performs one price calculation and does not track input tax, output tax, registration, invoices or partial exemption.
Why can an invoice differ by a penny?
Suppliers may round per line or at invoice level. Use the invoice method when reconciling a real purchase.