Sales Tax Calculator
Use our sales tax calculator to calculate sales tax, tax amount, and total price from a net price and sales tax percentage. Includes the formula to calculate sales tax, how to calculate sales tax backwards from total, plus quick tips for Excel and discounts.
What Is Sales Tax?
Sales tax is a tax added to the purchase of certain goods and services. It’s typically calculated as a percentage of the selling price and collected by the seller at checkout.
If you’re searching “calculate sales tax online” or “sales calculator with tax,” you usually want two numbers: the tax amount and the total price after tax.
Sales tax rules and rates vary by location, so the same net price can produce different totals depending on the sales tax rate.
Sales Tax Formulas
Sales tax is based on a net price (pre-tax amount) and a sales tax rate. You can also reverse-calculate the net price and tax amount from a total price that already includes tax.
Rate is the sales tax percentage (for example, 8.25).
Equivalent to Total = Net × (1 + Rate/100).
Use this when you need to calculate sales tax backwards from total.
After you compute Net from Total, subtract to get Tax.
A standard sales tax calculation.
Useful for receipts that only show a total with tax included.
This gives the effective sales tax percentage when you know net and total.
How to Calculate Sales Tax
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Enter the net price (pre-tax amount).
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Enter the sales tax rate as a percentage.
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The calculator returns the tax amount and the total (gross) price.
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If you only have a total price and the tax rate, use the backwards formulas: Net = Total/(1+Rate/100), then Tax = Total − Net.
Frequently Asked Questions
Tax = Net × (Rate/100). Then Total = Net + Tax.
Net = Total ÷ (1 + Rate/100). Then Tax = Total − Net.
If you know net and total: Rate% = ((Total − Net) ÷ Net) × 100. If you only know total and rate, you can’t derive the rate without additional info.
If net is in A1 and rate% is in B1, tax can be =A1*(B1/100) and total can be =A1*(1+B1/100). If you have total in C1 and rate% in B1, net is =C1/(1+B1/100).
In many cases, sales tax is calculated on the discounted price (the amount you actually pay before tax). However, rules vary by jurisdiction and discount type (store coupon vs manufacturer coupon), so check local guidance for your area.
Sales tax is a percentage-based tax collected on certain retail sales of goods and services. What’s taxable depends on the rules where the sale happens.
There isn’t one universal rate. Sales tax rates depend on location. If you know your rate, enter it in the calculator to compute tax and total.
It depends on your tax situation and local rules. Some people may be able to deduct certain sales taxes in specific contexts, but eligibility varies. If this matters for filing, confirm with official tax guidance or a tax professional.
A sales tax rate lookup is a tool or database that helps you find the correct sales tax rate for a specific address or jurisdiction. This calculator uses the rate you enter.