Sales tax calculator

What it does

Enter an amount and a tax rate. If the amount does not include tax, the calculator multiplies by the rate and shows the before-tax amount, the tax and the total. If you choose that the amount already includes tax, it divides the total by one plus the rate to find the before-tax amount, then shows the tax portion. Results are rounded to the cent. Because the quote, invoice and receipt makers take tax as an amount, this is the quickest way to get the number to type into them.

Use it when you write a quote, invoice or receipt by hand, check a supplier bill, or split a tax-included total from a market stall or event sale into its parts for your books. Because the document makers take tax as a dollar amount, calculate it here first and copy the tax figure across. Keep a note of the rate you used for each sale, since rates can differ between the places you sell and change during the year. Shipping and discounts may change the taxable amount in some states, so check which figure your state taxes before you calculate.

How to use it

1. Enter the amount.
2. Enter your combined sales tax rate.
3. Choose whether the amount already includes tax.
4. Copy the tax figure into your invoice or receipt.

Tips

• Use the combined state, county and city rate for the place of sale.
• Tax is rounded to the cent; your point-of-sale system may round per item.
• Store the before-tax amount in your books, and the tax separately.
• Some items are exempt; check your state’s rules.