Sales Tax Calculator

Two modes, two different divisions

In Add tax mode the tool multiplies the price by the rate and divides by 100, then adds the result to the price. With the defaults, 100 at 8.25% gives 8.25 of tax and a total of 108.25.

Remove tax mode cannot just take 8.25% off the total, because the tax was charged on the smaller pre-tax amount. Instead it divides the total by 1 + rate ÷ 100. Entering 100 as a tax-inclusive total at 8.25% gives a net price of 92.38 and tax of 7.62, noticeably less than 8.25.

A practical check: a receipt total of 54.13 in an 8.25% area breaks down to a net price of 50.00 and 4.13 of tax, which is exactly what a 50.00 item plus tax comes to.

The same price at common combined rates

The rate to enter is the combined rate for the point of sale: the state rate plus any county, city and special district additions. Four US states (Delaware, Montana, New Hampshire and Oregon) charge no state sales tax, and Alaska has no state rate but allows local sales taxes. Combined rates change when local measures pass, so confirm the current figure for the address.

Recovering the tax from a receipt total

Expense claims and bookkeeping often need the tax shown separately when a receipt only gives the total. Switch to Remove tax, enter the total and the local rate, and the Sales tax figure is the amount to record. A 1,200 total in an 8.875% area contains 97.82 of tax on a net price of 1,102.18.

If the receipt mixes taxable and exempt items, such as groceries and household goods in a state that exempts food, the reverse calculation will overstate the tax. Enter only the taxable subtotal.

Rounding and one-cent differences

• The tool keeps full precision internally and rounds each of the three figures to two decimals only for display. The raw tax on 249.99 at 7% is 17.4993, shown as 17.50, and the raw total of 267.4893 is shown as 267.49.
• Retail systems may round tax per line item rather than on the subtotal, which produces one-cent differences on multi-item receipts that this single-amount calculation will not reproduce.
• Some jurisdictions use tax tables or bracket schedules for small amounts instead of a straight percentage, so the tax on a very cheap item may legitimately differ from the figure here by a cent.
• Nothing is shown for an amount of zero or below, and a negative rate is rejected. A rate of 0% is accepted and returns the amount unchanged.

Sales tax versus VAT

Sales tax in the US and Canada is added at the register, so shelf prices are usually pre-tax and Add tax mode mirrors what happens at checkout. VAT and GST systems in Europe, the UK, Australia and elsewhere normally quote consumer prices with tax included, so you spend more time in the reverse direction. The arithmetic is identical, but the VAT Calculator on this site has preset buttons for common VAT rates and a copy button for a net, VAT and gross breakdown.