Sales tax · USD
United States
State-level examples only: California CDTFA and Texas Comptroller sales/use tax guidance.
These references are not an approval of a tax rate. The calculator applies a percentage you enter manually. Selecting United States changes the currency, not the applicable tax rules.
Official reference pages
- Know your sales and use tax rate California Department of Tax and Fee AdministrationPage content read during source research. Full rule validation remains pending.
- Sales and use tax Texas Comptroller of Public AccountsPage content read during source research. Full rule validation remains pending.
What still needs validation
These two states do not constitute national coverage. Build a state-by-state source register, transaction-date and sourcing rules, product taxability and location resolution. IRS deduction tools are not checkout-rate authorities; ZIP-only lookup is insufficient.
Before a rate can become a preset
Each executable rule needs a specific legal citation, jurisdiction, transaction category, tax base, effective period, exceptions and rounding policy. It also needs independent expected-result tests and recorded human approval. A retrieval date is not an effective date or a tax-professional sign-off.
Calculation method
For a single proportional percentage, add tax using net × rate ÷ 100. To extract included tax, divide the total by (1 + rate ÷ 100). This manual method does not determine whether that percentage legally applies.
Read the calculation and rounding limitations