Sales Tax Calculator: Add Tax to a Price

How to use this sales tax calculator

Enter the price before tax.
Enter the tax rate — add state, county and city rates together first if more than one applies.
Read the large figure: the total price including tax, with the tax amount alongside.

What sales tax is

A sales tax calculator adds tax to a price so you know the amount you will actually pay. You enter the price before tax and the tax rate as a percent, and it returns the tax amount and the total. It is useful when you are shopping, pricing a product for customers, or checking a receipt.

Sales tax rates vary, and a single purchase can carry several rates from different authorities. This calculator does not look up rates by location. If your rate combines state, county and city amounts, add those rates together first and enter the total — the result is only as accurate as the rate you provide.

Reading the price tag

The tag under the result shows the two prices every taxed purchase really has. The small figure at the top is the shelf price before tax, and the large figure is the amount you actually hand over at the till. The orange badge between them is the tax itself, so the gap between the shelf and the till is never a surprise.

The formulas

Tax amount

Tax amount = price × (rate ÷ 100)

Multiply the price before tax by the rate divided by 100. At $100.00 and 8.25%, the tax amount is $8.25.

Total price

Total price = price + tax amount

Add the tax to the price before tax. At the default figures the total price is $108.25.

Price before tax

Price before tax = total price − tax amount

The starting amount the tax was worked out on, shown alongside the tax and the total so the three figures can be checked against a receipt: $108.25 − $8.25 = $100.00.

Examples

Example	Price before tax	Tax rate	Tax amount	Total price
Default	$100.00	8.25%	$8.25	$108.25
Larger purchase	$250.00	7%	$17.50	$267.50
Small purchase	$59.99	6%	$3.60	$63.59

Three mistakes people make with sales tax

Applying the rate to the wrong amount

Tax is calculated on the price before tax, not on the total. On the default case, 8.25% of $100.00 is $8.25 — not 8.25% of $108.25. Always apply the rate to the pre-tax price.

Adding tax twice

Some prices already include tax. Adding tax again to a tax-inclusive price overstates the total. Check whether a displayed price includes tax before you calculate.

Using a rate that does not match your location

This calculator uses only the rate you enter; it does not look up rates by location. A rate from another state or city gives the wrong total. Confirm the combined rate that applies where you buy or sell.

Frequently asked questions

How do I calculate sales tax?

Multiply the price before tax by the tax rate as a decimal, then add the result to the price. For $100 at 8.25%, $100 × 0.0825 = $8.25, and $100 + $8.25 = $108.25.

What is the total on $250 at 7% tax?

The tax is $17.50 and the total is $267.50. The tax is $250 × 0.07 = $17.50, and $250 + $17.50 = $267.50.

What is the total on $59.99 at 6% tax?

The tax is $3.60 and the total is $63.59. The tax is $59.99 × 0.06 = $3.5994, which rounds to $3.60.

Does this calculator find my local sales tax rate?

No. It applies the rate you enter and does not look up rates by location. Find the combined rate that applies to your purchase, then enter it.

What if my area has state, county and city tax?

Add the separate rates together to get one combined rate, then enter that rate. The calculator applies a single rate, so it cannot calculate each layer separately.

Is this financial advice?

No. This calculator is a calculation aid for sales tax. It does not determine which rate applies to a transaction — that depends on where and what you buy.

Privacy and important information

This calculator runs entirely in your browser: your numbers are never sent to a server, stored, or shared. It is a calculation aid for sales tax, not financial advice.

Part of RahaKit's free finance calculators.

Sales Tax Calculator