Sales Tax Calculator
Add or remove sales tax from any amount at any rate. Get the tax amount and the pre-tax and after-tax totals instantly, right in your browser.
What this Sales Tax Calculator does
Sales tax is a consumption tax added to the price of goods and services at the point of sale. This calculator works both directions: it can add tax onto a listed price to find the final total you will pay, or remove (back out) the tax that is already baked into a tax-inclusive figure so you can see the original pre-tax price and the tax portion separately. It deliberately does not assume any jurisdiction's rate — you type in the exact percentage that applies to your purchase, so the answer is always correct for your city, county, or country.
The three modes
- Add sales tax to a price. Enter a price before tax and the rate. The tool multiplies the price by the rate to get the tax, then adds it to give the final total.
- Remove sales tax from a price. Enter a price that already includes tax. The tool divides it back out to reveal the original pre-tax amount and how much of the sticker was tax.
- Reverse a total into subtotal + tax. This is the same reverse math applied to a grand total — handy for filling in an invoice or expense report where you know only the amount paid and need the breakdown.
The formulas
Where rate is the tax percentage written as a decimal (for example 8.25% becomes 0.0825):
- Adding tax: tax = price × rate, and total = price + tax = price × (1 + rate).
- Removing tax: subtotal = total ÷ (1 + rate), and tax = total − subtotal.
Removing tax is not the same as simply subtracting the tax percentage from the total. Because the tax was calculated on the smaller pre-tax base, you must divide by (1 + rate) rather than multiply. Subtracting the percentage directly would overstate the tax and understate the original price.
How to use it
Pick a mode, enter the amount, and type your local sales tax rate as a percentage. The results update instantly: the sales tax portion, the pre-tax subtotal, and the total with tax, plus a one-line breakdown so you can sanity check the arithmetic. Nothing is transmitted to a server — the calculation runs entirely in your browser.
Worked example
Suppose an item is listed at $100.00 and the combined sales tax rate is 8.25%. In add mode, the tax is 100 × 0.0825 = $8.25, so the final total is $108.25. Now flip it around: if a receipt shows a tax-inclusive total of $108.25 at the same 8.25% rate, remove mode divides 108.25 ÷ 1.0825 to recover the original $100.00 subtotal, confirming the $8.25 of tax. The two modes are exact inverses of each other.
Rates differ widely by location and change over time, and some places apply additional district or special-purpose taxes on top of the base state rate. Always confirm the current combined rate for the exact address of the sale before relying on a figure for accounting or invoicing.