Everyday Life · Finance & Tax
VAT Calculator
Calculate the VAT amount and final price inclusive of VAT, or reverse-calculate the pre-VAT price from a VAT-inclusive total.
Calculator
Formula
P_ex is the price excluding VAT (the net price). r is the VAT rate as a percentage. P_inc is the price including VAT (the gross price). To add VAT, multiply the net price by (1 + r/100). To remove VAT from a gross price, divide by (1 + r/100). The VAT amount is always the difference between the gross and net prices.
Source: HM Revenue & Customs (HMRC) VAT guidance; European Commission VAT Directive 2006/112/EC.
How it works
Value Added Tax (VAT) is a consumption tax levied at each stage of the supply chain, with the final burden typically falling on the end consumer. In the UK, the standard VAT rate is 20%, with reduced rates of 5% for certain goods such as domestic energy, and 0% for essentials like most food and children's clothing. The European Union, Australia (GST), Canada, and over 160 other countries operate similar systems with varying rates. Understanding the difference between net (exclusive) and gross (inclusive) prices is fundamental to correct bookkeeping, invoicing, and compliance.
The core formula is straightforward. To add VAT to a net price, multiply by (1 + r/100), where r is the VAT rate percentage. For example, at 20% VAT: gross = net × 1.20. The VAT amount itself is simply gross minus net, or equivalently net × (r/100). To remove VAT from a gross price — often called a reverse VAT or ex-VAT calculation — divide the gross figure by (1 + r/100). This is a common mistake: many people incorrectly multiply the gross by the VAT rate percentage to find the tax component, which overstates the VAT amount.
This calculator is used daily by sole traders preparing invoices, shoppers comparing VAT-inclusive shelf prices against business purchase costs, developers building e-commerce systems, and finance students checking their work. It is equally applicable to any percentage-based tax that uses the same additive structure, such as GST in Australia or New Zealand.
Worked example
Example 1 — Adding VAT to a net price:
A freelance web designer charges a client £850.00 for a project. They are VAT-registered and must charge the standard UK rate of 20%.
VAT Amount = £850.00 × (20 / 100) = £850.00 × 0.20 = £170.00
Gross (VAT-inclusive) Price = £850.00 + £170.00 = £1,020.00
The invoice should show: Net £850.00 + VAT £170.00 = Total £1,020.00.
Example 2 — Removing VAT from a gross price:
A business purchases office supplies for £240.00 including VAT at 20% and needs to record the net cost for accounts.
Net Price = £240.00 ÷ (1 + 20/100) = £240.00 ÷ 1.20 = £200.00
VAT Amount = £240.00 − £200.00 = £40.00
Note: the incorrect method of £240.00 × 0.20 = £48.00 would overstate the VAT by £8.00 — a common and costly error.
Limitations & notes
This calculator assumes a single, flat VAT rate applied to the entire amount. Real-world transactions can involve mixed rates — for example, a restaurant bill that includes food at 0% VAT and alcohol at 20%. In those cases, each line item must be calculated separately. The tool does not account for VAT exemptions, partial exemption rules, margin schemes (used in second-hand goods trading), or the VAT flat rate scheme available to some small businesses in the UK. Currency symbols are not built in, so ensure you apply the result to the correct currency. Always verify the applicable VAT rate with your local tax authority, as rates change by government legislation and differ significantly between countries and product categories.
Frequently asked questions
What is the standard VAT rate in the UK?
The standard UK VAT rate is 20%, which applies to most goods and services. A reduced rate of 5% applies to items such as home energy and children's car seats, and a zero rate (0%) applies to most food, books, and children's clothing. Always verify the correct rate for your specific goods or services with HMRC guidance.
Why can't I just multiply a VAT-inclusive price by 20% to find the VAT?
Because the VAT was calculated on the net (lower) price, not on the gross total. At 20% VAT, the gross price is 120% of the net. Multiplying the gross by 20% gives 24% of the net — overstating the VAT by a factor of 1.2. The correct method is to divide the gross by 1.20 to get the net, then subtract to find the true VAT component.
What does 'net price' and 'gross price' mean in VAT terms?
The net price (also called the ex-VAT price) is the price before VAT is added — this is typically what a VAT-registered business charges to another VAT-registered business. The gross price (VAT-inclusive price) is the full amount paid, including VAT. Consumers generally see and pay gross prices on receipts and in shops.
Can I use this calculator for GST in Australia or New Zealand?
Yes. GST in Australia is 10% and in New Zealand is 15%, but the mathematical structure is identical to VAT. Simply enter the correct local rate in the VAT Rate field. The formulas for adding and removing the tax are exactly the same as for VAT in Europe.
Do I need to register for VAT, and what is the threshold?
In the UK, you must register for VAT if your taxable turnover exceeds £90,000 in any rolling 12-month period (as of 2024). Below this threshold, registration is voluntary. VAT-registered businesses charge VAT on sales, can reclaim VAT on eligible purchases, and must submit regular VAT returns to HMRC. Thresholds vary significantly by country, so consult your local tax authority.
Last updated: 2025-01-15 · Formula verified against primary sources.