Illustrative estimate. Check the rate and scheme eligibility for your transaction. No amounts are sent by this calculator.
Choose your base amount
Enter the starting amount and percentage. The first result is the percentage value; the second is the original amount plus that value. The third shows the starting base so you can verify which amount the rate was applied to.
Worked example
For £240 at 15%, multiply 240 × 15 ÷ 100 to get £36. Adding it gives £276. For a 15% discount on the same starting amount, subtract £36 instead to obtain £204. This tool displays the addition case, so it is important to distinguish increases from discounts.
A percentage increase is not its own reversal
Increasing £100 by 20% gives £120. Reducing £120 by 20% gives £96, not £100. To reverse the original 20% increase, divide £120 by 1.20. The reverse VAT calculator uses that division when extracting a net price.
Percentage points and rounding
A change from 5% to 6% is one percentage point and a 20% relative increase in the rate. Keep that distinction when comparing rates. The calculator accepts non-negative rates up to 100% and shows money to two decimals; it is a general arithmetic tool rather than a tax classification tool.
Quick answer
Can I use the result without saving an account?
Yes. Calculations run in your browser. Copy the figures into your own records; refreshing the page resets the inputs.
Keep learning
Educational information and estimates. These tools do not submit VAT returns or determine the treatment of a specific transaction.