RunTheTests

VAT / Sales Tax Calculator

Add or remove VAT (sales tax) from a price.

System verdict

RESULT

Gross (incl. tax): 120

Adding tax multiplies by the rate; removing it divides — you cannot just subtract the same percentage you would add, which is a common mistake.

Diagnostic telemetry
Gross (incl. tax)
120
Tax
20

What this cannot tell you

  • Pure arithmetic on the values you enter.

How this calculation works

Adding tax multiplies the net amount by the rate; removing it divides the gross by one-plus-the-rate. The two are not symmetric, which is the mistake this avoids.

What the results mean

Add vs remove
To add 20% you multiply by 1.2; to remove it you divide by 1.2 — not subtract 20%, which would be wrong.

Frequently asked questions

Why can’t I just subtract 20% to remove VAT?

Because the 20% was added to the net, not the gross. Removing it means finding the number that becomes the gross when increased by 20% — you divide by 1.2. Subtracting 20% of the gross takes off too much.

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