Sales Tax Calculator
Enter a price and tax rate to get the tax amount and total, or reverse a tax-inclusive total back to its pre-tax price.
Example
A $100.00 item with an 8.25% sales tax rate: tax = 100 × 0.0825 = $8.25, so the total is $108.25. Reversing it: a $108.25 total ÷ 1.0825 = $100.00 pre-tax, confirming $8.25 in tax.
How it works
In Add tax mode, tax = price × rate ÷ 100 and total = price + tax. In Remove tax mode, pre-tax price = total ÷ (1 + rate ÷ 100) and tax is the difference.
Good to know
This Sales Tax Calculator works two directions from the same screen. In "Add tax" mode you type a pre-tax price and a combined tax rate to see the sales tax and the final total. In "Remove tax" mode you type a tax-inclusive total instead, and it backs out the original price and the tax portion. It is handy for shoppers checking a register total, freelancers and small sellers sizing an invoice, and anyone reconciling a receipt where only the grand total is printed.
Reach for it whenever the price tag and the price you actually pay differ. Common moments: estimating an out-the-door cost before checkout, splitting a receipt and needing the pre-tax subtotal, or confirming a vendor charged the right rate. Because it runs entirely in your browser with nothing uploaded, you can paste in real purchase amounts without privacy concerns.
The result card leads with the headline figure for the mode you are in (total in Add mode, pre-tax price in Remove mode), then breaks out the three numbers that matter: pre-tax price, sales tax, and an effective rate. The effective rate is simply tax divided by the pre-tax base, so it should mirror the rate you entered; if it looks off, you probably typed a tax-inclusive number into Add mode or vice versa. A small table restates the same base, tax, and total so you can copy clean line items.
- Enter the combined rate (state plus county, city, and district), not just the state portion, or the total will come out low.
- Every figure is rounded to the cent, so a reversed total may land a penny off the original on edge cases.
- It assumes a single flat rate on the full amount, so it will not handle tax-exempt items, tiered rates, or shipping that is taxed differently.
Frequently asked questions
How do I find the pre-tax price from a receipt total?
Switch to Remove tax mode, enter the tax-inclusive total and the tax rate. The calculator divides the total by (1 + rate/100) to recover the original pre-tax price and shows the tax portion.
What tax rate should I enter?
Use your combined sales tax rate, which is the state rate plus any county, city, or district taxes that apply at the point of sale. For example, enter 8.25, not just the 6.25 state portion.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser; nothing is uploaded.
Is this financial advice?
No. These are educational estimates — consult a qualified financial professional before making decisions.
People also ask
How do you calculate sales tax on a purchase?
Multiply the pre-tax price by the tax rate expressed as a decimal: tax = price × (rate ÷ 100). For example, $100 at 8.25% is 100 × 0.0825 = $8.25, making the total $108.25.
How do you reverse-calculate sales tax from a total?
Divide the tax-inclusive total by 1 plus the rate as a decimal: pre-tax price = total ÷ (1 + rate ÷ 100). The tax is the difference between the total and that pre-tax price.
What is a combined sales tax rate?
It is the sum of the state rate plus any county, city, and special district rates that apply at the point of sale. The total you pay reflects this combined rate, not the state portion alone.
Is sales tax based on where I live or where I buy?
Sales tax is generally based on the location where the sale takes place or where the item is delivered, depending on the jurisdiction's sourcing rules. Rates can differ between two stores only a few miles apart.
Why does my calculated total differ from my receipt by a penny?
Rounding is the usual cause; tax is rounded to the cent and some retailers round per line item rather than on the order total. A one-cent gap on a single item is normal.
Does sales tax apply to shipping charges?
It depends on the jurisdiction and how shipping is billed; some states tax shipping when it is part of a taxable sale and others do not. A flat-rate calculator like this treats the amount you enter as a single taxable figure.
How do I find the sales tax rate for my location?
Sales tax rates are published by state revenue or taxation departments, and many provide ZIP code or address lookup tools that return the combined state and local rate.
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