How the checkout estimate works
Enter the pre-tax price in dollars and both tax rates as percentages from 0 to 100. Enter 0 for any tax that does not apply. Choose the additive method for a shared tax base or the compounded method when sales tax applies to the price plus excise tax.
Formula
Excise tax is the pre-tax price times the excise rate. Sales tax is the applicable base times the sales tax rate. Add both taxes to the pre-tax price for the checkout total. Effective tax rate is total tax divided by pre-tax price, times 100. At a zero price, the tax amounts and total are $0 and the effective rate is undefined.
Enter a $50 price, 8.25% sales tax and 15% excise tax. With the additive method, sales tax is $4.13 and excise tax is $7.50 for a $61.63 total. With the compounded method, the sales tax base is $57.50 and sales tax is $4.74 for a $62.24 total. These rates are hypothetical.
