Look on the price tag.

If you know the tax rate and the total, you can divide the total by (1+(tax rate)).

If you know the tax rate and the total, you can divide the total by (1+(tax rate)).

__Example__The amount paid, tax included is $105. The tax rate is 5%. What was the original price? (total paid) = (original price) + (tax rate)*(original price) (equation for the total including tax) (total paid) = (original price)*(1 + (tax rate)) (factor out the original price)**(total paid)/(1 + (tax rate)) = (original price)**(divide by the coefficient of original price) $105/(1+0.05) = $100**The original price was $100**. The amount of tax was $105 - $100 = $5 = 5%*$100