Sales Tax Calculator

[sun818]

Does anyone know the formula for a "reverse" sales tax calculator? Let's say I sell a blue widget for $20.00 including tax. How do I easily figure out what amount is the item price and what amount is the sales tax?

[jatar_k]

what are the sales tax percetages?

[marcs]

Say your sales tax is 7%.

Your $20.00 (including tax) is then 107%. To get to the amount before tax, divide 20 by 107 and multiply by 100 : 20.00/107*100 = $18.69

[jatar_k]

exactly :)

[Conard]

Or,
Just divide the 20.00 by 1.07 for 7% tax.

[sun818]

Thanks! :) I plugged in the formulas into Excel and it works great!

Sales Tax:
total - (total / (1 + salestaxrate))
example: $20 - ($20 / 1.0825)

Subtotal:
(total / (1 + salestaxrate))
example: ($20 / 1.0825)