If you already know the total price including VAT and want to extract the tax portion, you need to reverse the VAT calculation instead of subtracting the percentage directly from the total.
To find the net amount, divide the gross amount by one plus the VAT rate as a decimal. For example, if the VAT rate is 21%, divide the gross amount by 1.21. The difference between the gross amount and the net amount is the VAT amount.
If a total invoice amount is 121 and the VAT rate is 21%, the net amount is 121 / 1.21 = 100. The VAT portion is then 121 - 100 = 21.
If you do not want to work through the formula manually, use the VAT Calculator. Switch the calculator to remove-VAT mode, enter the gross price, and the page will return the net amount and VAT amount immediately.
This type of calculation is common when checking invoices, separating tax from retail receipts, validating pricing, or converting reported totals back to pre-tax amounts.
No. That gives the wrong answer because the VAT percentage was applied to the net amount, not the gross amount. You need to divide by 1 plus the VAT rate.
Yes. Replace 1.21 with 1 plus the applicable VAT rate in decimal form. For 9%, divide by 1.09. For 6%, divide by 1.06.
Use the VAT Calculator if you want the net amount, gross amount, and VAT amount without doing the math manually.