VAT calculator: questions and guides

Each guide here answers one question with a practical example, then takes you to the tool to try it yourself. Guides: 25.

Questions

How to add VAT to a price, or take it outHow to add VAT to a price, how to take it out of a price that already includes it, and why subtracting 15% from the final price gives the wrong number.
I want the customer to pay a round 99 including VAT; what is my price before tax?Start from a round tax-inclusive shelf price like 99 and work back to the net price for your store, at the rate you enter, then check the profit still works.
The VAT on my invoice differs from the calculator by one cent; which one is right?Why invoice VAT can differ by a cent from a calculator: rounding each line versus rounding the total once, shown with a worked example.
A client asks whether my quote includes VAT; how do I work out the total to put on it?For freelancers who charge VAT: work out fee, tax and total at the rate you enter, and show all three on your quote so the client never has to guess.
My marketplace deducts its commission with VAT on top; how do I split the fee and the tax from my statement?Your marketplace deducts its commission plus VAT. Split that statement line into net fee and tax, using the rate printed on the platform's own fee invoice.
My invoice has lines at different VAT rates and some at zero; how do I calculate it with the calculator?The calculator applies one rate to one amount, so handle a mixed invoice by grouping lines per rate, running each group, then adding the results. Worked example.
My store prices include VAT; how do I work out my real profit margin?If your prices include VAT, extract the tax first and measure margin on the net price, or you will count the tax as profit. Worked example with real figures.
Does the VAT calculator work for Bahraini dinar or Omani rial prices with three decimals?The maths inside is exact, but results display with two decimals even for Bahraini dinar or Omani rial. Here is how to use it and round to fils yourself.
I sell to customers in the US or Australia; can I use the same calculator for sales tax or GST?The calculator works for any tax charged as one percentage of the net amount, such as sales tax or GST. Here is what to do when several rates stack on the same sale.
If the VAT rate changes, how do I recalculate my tax-inclusive prices?When the rate changes, do not add the point difference to your shelf price. Extract the net at the old rate, then add the new rate. Worked example with real figures.
Is it safe to enter my clients' invoice amounts into the VAT calculator?The calculation runs inside your browser, and no amount is sent to a server or saved. What that means in practice, and what stays your responsibility.
My receipt shows 13.04 of tax on a total of 100; is that wrong if the rate is 15%?Why tax looks smaller than the stated rate when you measure it against the total: the rate applies to the net amount. Explained with figures from the calculator.
How do I estimate the VAT I will owe from the tax on my sales minus the tax on my purchases?A rough figure for the cash to set aside: extract the tax from total sales and total purchases, then subtract. An arithmetic estimate only, not a tax return.
I worked out my price with the selling-price calculator; how do I turn it into the tax-inclusive price customers see?The selling-price calculator gives a price before tax. Add tax at the rate you enter, and if you round the shelf price, extract it again to check your net.
My Amazon listing price is shown including VAT; how much revenue is mine before fees?When a marketplace shows tax-inclusive prices, extract the tax to find your net revenue per sale, then subtract fees from your settlement report. At the rate you enter.
Should I work out VAT with an Excel formula or use the calculator?When a spreadsheet formula is faster, when the calculator is better, and how it catches the common mistake of multiplying the gross by 0.85. With real figures.
One supplier quotes 1,000 plus VAT and another 1,120 including VAT; which is cheaper?Never compare two quotes on different bases. Add tax to one or extract it from the other at the same rate, then compare. The bigger number can be the cheaper one.
Should my product cost include the VAT I paid the supplier or not?If you reclaim purchase tax it is not a cost, so use the net amount; if you cannot, the full amount is your cost. How to extract the net and how the margin moves.
A customer returned an item bought for 230 including VAT; how much of the refund is tax?Split a refund into net sale and tax at the rate charged on the original sale, so your sales and tax records both come down by the right amount.
If I give 10 off a VAT-inclusive price, why doesn't my income fall by the full 10?Part of a fixed discount on a tax-inclusive price comes out of the tax, not your income. Extract the discount at your rate to see how much your net really falls.
I sell in both Saudi Arabia and the UAE; how do I calculate tax for each country at its own rate?Run the same net price twice, once with each rate you have confirmed for each country, and keep two separate price lists. The tool never assumes any country's rate.
I keep mixing them up: when do I choose add VAT and when extract VAT?One question settles it: is the number in front of you before tax or already including it? Everyday seller examples, and what happens if you pick the wrong mode.
A client paid a 50% deposit including VAT; how do I separate the tax in the deposit?Extract the tax from a deposit at the same rate as the full price, so the deposit carries its share of the project's tax and the balance carries the rest. Worked example.
I set Shopify to show prices including tax; how do I check the tax it calculates is right?With tax-inclusive prices, an order's tax should equal extracting the price at your configured rate. How to test one order, and what a mismatch usually means.
I typed the rate as 0.15 instead of 15 and the tax came out tiny; how should I enter the rate?The rate field takes a percentage, so 0.15 means 0.15%, not 15%, and the tax comes out a hundred times too small. How the Rate you entered line exposes it.