Sales Tax Calculator

Calculate sales tax on any purchase and find the pre-tax or after-tax price instantly.

100% Free No Sign-Up Calculated in Your Browser

Calculation Direction

Pre-Tax Price

Sales Tax Rate (%)

Common US State Rates

After-Tax Total

Pre-Tax Price

Sales Tax

Tax Rate

After-Tax Total

Quick Reference: Tax at Common Rates

Rate	Pre-Tax	Tax	Total

Add sales tax to a pre-tax price, or strip tax back out of an after-tax total, using any tax rate you enter or a quick-pick common US state rate.

How It Works

How Sales Tax Calculator Works

In "add tax" mode, the calculator treats your entered amount as the pre-tax price and simply computes tax = price × (rate ÷ 100), then adds it on: total = price + tax. In "remove tax" mode, it works in reverse — your entered amount is treated as the already-taxed total, so the pre-tax price is found by dividing: pre-tax = total ÷ (1 + rate ÷ 100), with the tax portion being the difference between the two.

The state-rate buttons simply fill in a commonly cited base statewide sales tax percentage for that state so you don't have to look it up — they don't attempt to add county or city sales tax on top, which in many states can raise the real combined rate noticeably above the state-level figure shown.

The quick-reference table reruns the tax calculation on your pre-tax price across several common rates (0% through 12%) side by side, so you can compare how much tax the same purchase would generate in different tax jurisdictions.

Worked Example

See It In Action

With the default $100 pre-tax price and an 8.5% tax rate in "add tax" mode: tax = 100 × 0.085 = $8.50, making the after-tax total $108.50. Switching to "remove tax" mode with $108.50 entered as the after-tax total reverses this: pre-tax price = 108.50 ÷ 1.085 = $100.00, confirming the two modes are exact inverses of each other.

Real-World Use Cases

Who Uses Sales Tax Calculator and Why

Adding sales tax to a quoted pre-tax price to find the actual amount you'll pay at checkout.
Reconstructing the pre-tax price of a purchase from a receipt that only shows the final after-tax total, useful for expense reporting.
Comparing how the same purchase would be taxed across a range of common tax rates using the quick-reference table.
Getting a starting-point state sales tax rate via the quick-pick buttons before adjusting for local county or city tax.

Common Mistakes

Mistakes to Avoid

Assuming the state quick-pick button gives your exact checkout tax rate — it only reflects the general statewide base rate, and many states allow counties and cities to add their own local sales tax on top.
Using "add tax" mode on an amount that's actually already a final receipt total — that will double-tax the purchase; use "remove tax" mode instead when you only have the after-tax total.
Forgetting that if your purchase is subject to combined state and local tax, you should enter the full combined rate manually rather than relying solely on the state button.

Pro Tips

Tips for Best Results

If you know your local combined rate (state plus city/county), enter it directly rather than relying on the state quick-pick button alone.
Use "remove tax" mode whenever you're working backward from a receipt total to figure out the pre-tax item price for bookkeeping or expense reports.

Troubleshooting

Fixing Common Problems

My real receipt total doesn't match the calculator's tax amount. — Check whether your local jurisdiction adds county or city sales tax on top of the state rate — the state quick-pick buttons only reflect the statewide base rate, not any local additions.

Glossary

Terms Explained

Add tax mode: Treats your entered amount as the pre-tax price and calculates the after-tax total by adding tax on top.

Remove tax mode: Treats your entered amount as an already-taxed total and works backward to find the original pre-tax price.

FAQ

Frequently Asked Questions

When should I use "remove tax" instead of "add tax"?

Use "remove tax" when you only know the final receipt total and want to know how much of it was the actual item price versus tax — for example, reconstructing a pre-tax amount for expense reporting or accounting.

Are the state rate buttons the exact tax rate I'll pay at checkout?

Not necessarily — they show each state's general statewide base sales tax rate. Many states also allow counties and cities to add their own local sales tax on top, so your actual combined rate at the register can be higher than the button shown.

Why does the tax amount round the way it does?

The calculator computes tax as an exact percentage of the price and displays it rounded to the nearest cent, matching how sales tax is generally applied and rounded at checkout.

Can I use this for a purchase with multiple tax rates, like combined state and local tax?

Yes — just enter the full combined rate (state plus any local sales tax that applies to your purchase) in the tax rate field rather than relying solely on the state quick-pick button, which only reflects the state-level rate.