Finance
US Sales Tax Calculator
Add US sales tax or find a before-tax price using your own combined rate.
Your details
Enter your details below
Your result
Based on the values you enter
Enter the applicable combined rate for the taxable amount only. No state or local rate lookup, exemption checks or mixed-rate baskets. All amounts are USD.
Useful next checks
- Compare a few scenarios before making a decision.
- Check rates, fees, tax, and timing outside the estimate.
- Use the explanation below to understand the formula.
Intro
Use this US sales tax calculator to work out the tax on a taxable purchase and its total price in dollars. Enter the combined sales tax rate that applies to your purchase. No state or local rate is assumed or looked up.
What this sales tax calculator does
Choose Add tax to calculate sales tax on a price before tax. Choose Before-tax price to estimate the original price from a total that already includes sales tax. Both modes show the price before tax, sales tax and total including tax in USD, regardless of your selected site region.
Use one applicable rate for the whole taxable amount. For a mixed basket, calculate separately for each tax rate and keep exempt items separate. The calculator does not decide what is taxable.
How to use it
- Enter the amount in US dollars, with up to two decimal places.
- Enter your combined sales tax percentage, such as 8.25 for 8.25%, rather than 0.0825. Rates can have up to six decimal places, including 8.875%.
- Choose Add tax for a before-tax amount or Before-tax price for a total that already includes tax.
- Read the three labeled amounts and check that your rate applies to the entire amount entered.
The rate field starts blank deliberately. Confirm the applicable rate with the official tax authority for the transaction. A state rate alone may omit local taxes. California's tax authority explains district taxes and provides an address lookup; New York's guidance explains combined rates, jurisdiction and transaction-specific exceptions. These sources illustrate why a location and purchase can matter; this tool does not implement either state's rules.
How it works
Let P be the taxable price before tax and r be the percentage rate divided by 100.
- Sales tax = P × r, rounded to the nearest cent.
- Total including tax = P + rounded sales tax.
- Before-tax estimate = total including tax ÷ (1 + r), rounded to the nearest cent.
- In reverse mode, estimated tax = total − rounded before-tax estimate.
Half-cent ties round up. The displayed amounts always add up. Reverse mode is an estimate for a single uniform rate: it may not reproduce a receipt that rounded each item separately. Removing 8.25% tax is not the same as subtracting 8.25% of the total, because the tax was based on the price before tax.
Example calculation
For an illustrative taxable purchase of $80 at 8.25%:
- Tax = $80 × 0.0825 = $6.60.
- Total = $80 + $6.60 = $86.60.
- Working backward: $86.60 ÷ 1.0825 = $80.00 before tax.
For a second illustrative purchase of $47.50 at 8.875%, unrounded tax is $4.215625. It rounds to $4.22, giving a $51.72 total. These percentages are examples, not a rate recommendation for any location or product.
How to use the result
Use the result to estimate a purchase total or check simple single-rate arithmetic. Confirm the tax treatment of the transaction before using the number for business records. For a taxable price after a discount, first establish the correct taxable amount under the applicable rules; this tool does not decide which discounts or charges change the tax base.
Assumptions and limitations
- One user-entered rate applies to the entire amount. No state, county, city, district or ZIP-code rate database is maintained.
- Exemptions, tax holidays, product categories, seller obligations, use tax, shipping, discounts and special fees are not determined.
- Amounts from $0 to $1 billion are supported; rate inputs range from 0% to 100%. These are tool limits, not statements of tax law.
- Money accepts up to two decimal places; rates accept up to six. Tiny positive tax below half a cent rounds to $0.00 and is labeled accordingly.
- A reverse result estimates a single-rate subtotal; original line-item rounding can produce a different receipt breakdown.
- This is a calculation aid, not tax or legal advice, a tax-filing tool or an invoice system.
Frequently asked questions
Is sales tax the same as VAT?
No. They are different tax systems. The percentage arithmetic can look similar for a single price and rate. Use the VAT Calculator when adding or removing VAT; changing a currency does not change tax rules.
Can the calculator tell me which rate to charge?
No. You supply the applicable combined rate. Consult the appropriate official authority for jurisdiction, product and transaction rules.
Can I use zero?
Yes. A zero rate gives zero tax and leaves the amount unchanged. A zero amount also gives zero tax. An empty rate is not treated as zero.
Does this calculator find the sales tax rate for my state or ZIP code?
No. Enter the combined rate that applies to your taxable purchase. State, local, district and product-specific rules can differ; use the appropriate official tax authority to confirm your rate.
How do I find a price before sales tax?
Choose Before-tax price, enter the total including tax and the applicable rate. The calculator divides the total by 1 plus the rate as a decimal, then estimates the before-tax price to the nearest cent.
Can I enter a rate such as 8.875%?
Yes. Enter 8.875 in the rate field. Rates from 0% to 100% with up to six decimal places are supported. These are calculation limits, not official rates.
Why can this differ from a receipt?
This tool applies one rate to the whole supplied amount. Mixed tax rates, exempt items, shipping, discounts and per-item rounding can produce a different receipt total. Reverse calculations are estimates.