How Is VAT Calculated in the UK? Simple VAT Calculation Guide

How is VAT calculated in the UK?

VAT is usually calculated by applying the right VAT rate to your net price. In most cases, that means multiplying the net price by 1.20 for the standard rate, 1.05 for the reduced rate, or leaving it unchanged for zero-rated goods and services. The UK’s main VAT rates are 20%, 5%, and 0%. 

If you need to remove VAT from a VAT-inclusive price, divide the gross amount by 1.20 or 1.05 to get back to the net figure. That gives you a quick way to check quotes, supplier bills, and your own pricing before you send a VAT invoice. 

VAT calculation method explained

The simplest VAT calculation method is:

The multiplier works because you’re adding the VAT rate to the original price. So with 20% VAT, you’re working with 100% + 20% = 120%, which becomes 1.20. With 5% VAT, it becomes 105%, or 1.05. 

That’s the method most businesses use day to day when pricing work, checking supplier invoices, and preparing VAT returns.

UK VAT rates at a glance

The standard VAT rate in the UK is 20%. A reduced rate of 5% applies to some goods and services, and some supplies are zero-rated. HMRC also treats some items as exempt, which is different from zero-rated because exempt sales are generally handled differently for VAT recovery and reporting. 

If you’re not sure which rate applies, check HMRC’s guidance on VAT rates for different goods and services before raising an invoice. Using the wrong rate can affect your pricing, your return, and how much VAT you can reclaim. 

How to calculate VAT step by step

1. Start with the net price

This is the price before VAT is added.

Example:
A service costs £200 before VAT.

2. Check the correct VAT rate

Most businesses use the standard 20% rate, but some goods and services fall into the 5% or 0% categories. HMRC’s rate guidance is the best place to check edge cases. 

3. Apply the formula

For standard-rate VAT:

£200 × 1.20 = £240

That means:

• Net price: £200
• VAT: £40
• Gross price: £240

For reduced-rate VAT at 5%:

£200 × 1.05 = £210

That means:

• Net price: £200
• VAT: £10
• Gross price: £210

4. Show VAT clearly on the invoice

If you and your customer are both VAT registered, you must use a VAT invoice with the extra information HMRC requires. That includes the VAT amount and other invoice details beyond a standard invoice. 

If you need a refresher on invoice formatting, see our guide on how to create an invoice.

How to remove VAT from a price

Sometimes you’ll get a VAT-inclusive figure and need to work backwards.

Use these formulas:

• 20% VAT: Gross price ÷ 1.20
• 5% VAT: Gross price ÷ 1.05

Example:
You receive a supplier invoice for £120 including VAT.

To find the net amount:

£120 ÷ 1.20 = £100

To find the VAT amount:

£120 – £100 = £20

This is useful when you’re checking purchase invoices, reviewing expenses, or working out what you may be able to reclaim through your VAT refund.

How to calculate the VAT amount only

Sometimes you don’t need the full gross price. You just need the VAT amount.

Use:

• VAT amount at 20% = Net price × 0.20
• VAT amount at 5% = Net price × 0.05

Example:
A product costs £85 before VAT.

At 20% VAT:

£85 × 0.20 = £17 VAT

Total price including VAT:

£85 + £17 = £102

If you already know the gross figure instead, work out the net amount first, then subtract it from the gross price.

VAT calculation examples for common business situations

Adding VAT to your sales price

If you sell a product for £500 before VAT and the standard rate applies:

£500 × 1.20 = £600

You’d charge:

• £500 net
• £100 VAT
• £600 total

Removing VAT from a supplier bill

If a software subscription costs £60 including VAT:

£60 ÷ 1.20 = £50 net

So:

• Net cost: £50
• VAT: £10
• Gross cost: £60

Working with the reduced 5% rate

If an item costs £80 before VAT and the reduced rate applies:

£80 × 1.05 = £84

So:

• Net price: £80
• VAT: £4
• Gross price: £84

Working with zero-rated sales

If a sale is zero-rated, the gross and net amount are the same. You still need to record it properly, and zero-rated sales can still count towards the VAT registration threshold. 

How to calculate the VAT you owe HMRC

For VAT returns, the usual method is:

Output VAT – Input VAT = VAT due

• Output VAT is the VAT you charge customers
• Input VAT is the VAT you pay on eligible business purchases

If output VAT is higher, you pay the difference to HMRC. If input VAT is higher, you may be able to reclaim the difference. This is the basic approach most VAT-registered businesses follow when filing returns. 

Example:
You charge £8,000 in output VAT over the quarter.
You pay £5,500 in input VAT on eligible business costs.

£8,000 – £5,500 = £2,500

You’d usually owe £2,500 to HMRC for that period.

If you’re still getting set up, our guide on registering for VAT can help.

When do you need to register for VAT?

You must usually register for VAT if your taxable turnover goes over £90,000 in the last 12 months, or if you expect it to go over £90,000 in the next 30 days. Businesses can also choose to register voluntarily below that threshold. 

If you’re close to the threshold, it’s worth keeping a close eye on turnover and sales timing. Leaving registration too late can create avoidable admin, backdated VAT issues, and penalties. 

For the most up-to-date information, visit the official guide on when to register VAT on GOV.UK.

VAT invoices, records, and filing

HMRC requires VAT-registered businesses to keep VAT records and issue VAT invoices in the right format where needed. Most VAT-registered businesses also need to follow the rules for Making Tax Digital for VAT, which means keeping digital records and submitting returns through compatible software. 

That matters because VAT calculation is not just about pricing. It affects:

• your invoices
• your bookkeeping
• your reclaimable VAT
• your quarterly filing position

If your numbers are right but your records are messy, VAT still becomes harder than it needs to be.