Free USA Tax Calculator Online
Calculate exact sales tax and excise tax for all 50 US states instantly. Define your own product categories, set custom tax rules, and get precise results — free, no signup needed.
Step 1 of 5 · State Selection
Where is this product being sold?
Select the US state to apply the correct tax jurisdiction.
How to Use This Tax Calculator
Select State
Choose the US state where the product is sold and confirm its tax status.
Add Categories
Type your own product category names — any label, no restrictions.
Set Tax Rules
Pick a formula (% cost, % sale, flat, per mL, per weight) and enter the rate.
Enter Details
Input quantity, sale price, and required fields for the chosen formula.
Get Results
See subtotal, tax per unit, total tax, and grand total instantly.
Why Use Our Free Tax Calculator?
Frequently Asked Questions
How accurate is this tax calculator?
Our calculator uses exact formulas verified against real US state excise tax logic: percentage of cost price, percentage of sale price, flat rate per unit, per milliliter, and per weight unit. All calculations use unrounded intermediate values to avoid compounding rounding errors.
Which US states are supported by this tax calculator?
All 50 US states plus Washington DC are supported — 51 tax jurisdictions in total. Each state can be marked as taxable or exempt based on your product type.
Can I define my own product categories?
Yes — you can create any category name. The tool is fully generic and works for any industry: retail, beverages, electronics, food, apparel, and more.
What tax formulas does this calculator support?
Five formulas: Percentage of Cost Price (e.g. 52% of what you paid), Percentage of Sale Price (e.g. 10% of retail price), Flat Dollar per Unit (fixed amount per item), Dollar per mL (for liquid volume-based excise taxes), and Dollar per Weight Unit (for weight-based taxes).
Is this tax calculator free to use?
Yes, completely free with no hidden charges, no account required, and no limitations. It runs entirely in your browser — no data is sent to any server.
Does the tax calculator work on mobile?
Yes. The calculator is fully responsive and works on smartphones, tablets, and desktop computers.
How do I calculate sales tax for multiple states?
Use the 'New State' button after getting your result to start a new calculation with a different state while keeping your categories and rules. Or use 'Start Over' to reset everything.
About This USA Tax Calculator
This free USA tax calculator helps businesses, accountants, and developers calculate sales tax and excise tax across all 50 US states and Washington DC. Unlike generic tax tools, this calculator lets you define your own product categories and choose from multiple tax formulas to match your state's specific tax structure.
The tool supports five calculation methods used in real US state tax codes: percentage of cost price, percentage of sale price, flat dollar per unit, per milliliter (common in liquid-based excise taxes), and per weight unit. Each formula mirrors standard excise tax calculation methodology used by state revenue departments.
Built by ToolLabHQ as part of our open-source tool collection. All calculations run locally in your browser — no data is stored or transmitted anywhere.