Sales Tax Calculator

How to read your result

Subtotal, sales tax, and total always satisfy Subtotal + Tax = Total, whichever direction you calculate in. Adding tax multiplies the subtotal by (1 + rate); finding the subtotal from a total divides by the same factor — the two are exact opposites, and dividing is never the same as subtracting the percentage, which is the most common sales tax mistake. Pick your state for a combined average rate, or switch to Custom rate and enter the exact combined rate for your city and county if you need precision beyond the state average.

Sales tax formulas

Worked example

A $50.00 subtotal at an 8% combined rate: tax = 50 × 0.08 = $4.00, so the total is $54.00. Going the other way from that same $54.00 receipt total, the subtotal is 54 ÷ 1.08 = $50.00, confirming the round trip — and the tax was $4.00 either way. The mistake to avoid is subtracting 8% directly from $54: that gives $49.68, and checking it forward proves the error — $49.68 × 1.08 = $53.65, not $54.00.

US combined sales tax rates by state

Combined rate = statewide rate + population-weighted average local (city/county/district) rate, from the Tax Foundation's midyear 2026 report. Your exact local rate can be higher or lower than the state average — use the calculator's Custom rate option for a specific address.

Assumptions

• Sales tax is modelled as a simple percentage of the subtotal, applied once at the point of sale — the standard US retail sales tax structure.
• State presets use each state's population-weighted AVERAGE combined rate (Tax Foundation, midyear 2026) — a starting estimate, not the rate for any one specific address.
• Rounding is to the nearest cent, matching how sales tax appears on a real receipt.
• Every item entered is assumed taxable at the same rate — mixed-taxability carts (e.g. some groceries exempt) need the exempt items entered separately or excluded.

Limitations

• No product-level taxability rules — many states exempt or reduce tax on groceries, clothing, or prescription drugs; this calculator applies one rate to the whole amount you enter.
• No special district, transit, or resort taxes layered on top of the state+local combined rate in specific zones.
• Not a filing, remittance, or nexus tool — it does not determine where a business owes sales tax or produce a return.
• State averages are not city- or county-specific; two addresses in the same state can have meaningfully different combined rates.

This is an estimate, not a filed computation. For VAT/GST outside the US see the VAT/GST calculator; for income tax see the income tax calculator.

Frequently asked questions

Related calculators

Tools that build on the same price and percentage maths:

• VAT/GST CalculatorAdd or remove VAT, GST, or HST from a price, solve tax-inclusive and tax-exclusive values, and build mixed-rate invoices.
• Income Tax CalculatorEstimate income tax with custom progressive bands, a sourced US federal mode, refund or amount owed, and scenario comparison.
• Salary & Take-Home Pay CalculatorEstimate take-home pay with sourced payroll models for the US, India, UK, Canada, and Australia, plus a net-to-gross solver.
• Percentage CalculatorSolve X% of Y, what percent X is of Y, reverse percentage, increase/decrease, discounts, and tax, tip, or commission.
• Markup CalculatorPrice from cost across nine modes — markup, target margin, reverse cost ceilings, and ecommerce landed cost after fees.

Read the guide

For how VAT, GST, and US sales tax relate and where the maths overlaps, see VAT, GST, and Sales Tax Calculations Explained With Examples.

For what a tax estimate captures and when to check official sources instead, see Why Tax Calculators Are Estimates and When to Check Official Sources.