VAT is the most familiar of percentage mark-ups: it is applied to the net price to obtain the final one. The tricky point is the inverse operation, that is, working back from the VAT-inclusive price to the taxable amount.

Definition — VAT and stripping it out

VAT (value added tax, in Italy 22%22\% standard, 10%10\% reduced, 4%4\% super-reduced) is computed on the taxable price: Pivato=Pimponibile(1+i),P_{\text{ivato}} = P_{\text{imponibile}}\cdot(1+i), where ii is the rate in decimal form (i=0,22i=0{,}22 for 22%22\%). To strip out the VAT from a VAT-inclusive price we divide: Pimponibile=Pivato1+i.P_{\text{imponibile}} = \frac{P_{\text{ivato}}}{1+i}.

Applying VAT means multiplying by (1+i)(1+i); stripping it out means dividing by the same factor. It is not the same as taking the rate off the VAT-inclusive price, as the stripping-out example shows.

Topics: Percentages
Concepts: VAT · Stripping out VAT
Skills: Using formulae