VAT and Sales Tax Explained: Adding, Removing and Avoiding Errors
Prices are quoted with tax in some countries and without it in others, and moving between the two correctly matters for invoices, shop pricing and personal budgets. One common mistake, subtracting the rate instead of dividing by it, shifts a total by several per cent.
How VAT works
Value-added tax is charged at each stage of production and sale, but registered businesses usually reclaim the VAT they paid, so the final consumer bears the cost. The arithmetic at the till is simple: a net price of 100 with 22% VAT becomes 100 × 1.22 = 122.00, of which 22.00 is tax.
Because the rate is applied to the net figure, the tax is always a share of the pre-tax price, never of the final total. Use the VAT Calculator for both directions and read the three figures it returns: net, VAT and gross.
How sales tax works
Sales tax is charged once, at the point of sale to the final customer, rather than at every stage. For the customer the arithmetic is identical to VAT, but the rate is often a combination of state, county and city rates, so the effective percentage can differ from the headline state figure.
Add the components before you calculate: a 6% state rate plus a 2% local rate is 8% on the price, not 6% and then 2% on the result. The Sales Tax Calculator accepts the combined rate you enter, which keeps the result aligned with your receipt.
Removing tax from a gross price
This is where most errors happen. If a gross price already includes tax, subtracting the rate is wrong because the tax was calculated on the smaller, net amount. Divide by (1 + rate) instead. For a 246 gross price at 20%:
- Net = 246 ÷ 1.20 = 205.00.
- VAT = 246 − 205.00 = 41.00.
- Check: 205.00 × 1.20 = 246.00, so the figures are consistent.
- The wrong route, 246 × 0.80 = 196.80, understates the net by 8.20 and overstates the tax.
On an invoice the three lines must add up exactly. If they do not, the rate or the direction is almost always the cause.
Adding and removing tax at a glance
The same rate behaves differently depending on which direction you travel. This table starts from 100 net and from 120 gross:
| Rate | Net 100 | Gross 120 | Tax inside |
|---|---|---|---|
| 5% | 105.00 | 114.29 | 5.71 |
| 10% | 110.00 | 109.09 | 10.91 |
| 20% | 120.00 | 100.00 | 20.00 |
| 22% | 122.00 | 98.36 | 21.64 |
| 25% | 125.00 | 96.00 | 24.00 |
Notice that a higher rate produces a lower net from the same gross: 120 gross contains 114.29 of net at 5% but only 96.00 at 25%.
A basket with two rates
Reduced rates apply to some goods and the standard rate to others, so a single receipt can mix both. Suppose a basket holds 60 of goods at 20% and 40 at 5%:
- Tax on the first part: 60 × 0.20 = 12.00.
- Tax on the second part: 40 × 0.05 = 2.00.
- Total tax: 12.00 + 2.00 = 14.00.
- Gross total: 60 + 40 + 14.00 = 114.00.
The effective rate is 14 ÷ 100 = 14%, between the two rates but closer to the larger share. Applying one blended rate to the whole basket would give the same total here only because the net shares happen to be round.
Pricing for profit
Decide the pre-tax selling price first, using cost plus a markup with the Markup Calculator, and add tax afterwards. If you work backwards from a tax-inclusive shelf price, remember that the tax is not part of your revenue: 122 gross at 22% is 100 of revenue and 22 that belongs to the tax authority.
The markup versus margin guide explains why a target margin needs a larger markup, and the percentages guide covers the stacked-discount arithmetic that often sits next to tax on the same invoice.
Mistakes that appear on real invoices
- Subtracting the rate from a gross price. Divide by 1 + rate; subtracting understates the net.
- Applying the wrong rate. Reduced-rate goods need their own rate, not the standard one.
- Rounding each line separately. Round the total, or the invoice can be a cent out.
- Mixing net and gross in one column. Label every column so the reader knows which side of the tax it sits on.
- Using an old rate. The tools use the rate you type in; confirm the current figure with the tax authority.
Frequently asked questions
A gross price of 246 includes 20% VAT. What is the net?
205.00, from 246 ÷ 1.20. The VAT is 41.00, and 205.00 × 1.20 returns 246.00.
How much VAT is added to 80 at 22%?
17.60, so the gross price is 97.60, from 80 × 0.22 added to 80.
Why is taking 22% off 122 the wrong way to find the net?
It gives 26.84 instead of 22.00, because the 22% was charged on the net figure. Divide by 1.22: 122 ÷ 1.22 = 100, and the tax is 22.
Do VAT and sales tax differ for the customer?
The arithmetic is the same; the difference is where and how often the tax is collected. Use the rate that applies to your purchase and the combined local rate where one exists.
- VAT Calculator – Add VAT to a net price or extract VAT from a gross price.
- Sales Tax Calculator – Add sales tax to a price or find the tax in a total.
- Markup Calculator – Calculate selling price from cost and markup.
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This guide is for general information and is not financial, tax, legal or medical advice. See our disclaimer.