Quality Standards
The bar every figure on this site has to clear before it's published, and stays held to afterward.
Before a figure is published
- It is tied to a specific official source: a government page, a statute, or an official fee schedule, not an estimate carried over from another site.
- It is checked against the actual rule, including exceptions like tax caps, minimum taxes, and whether a trade-in reduces the taxable amount.
- If sources disagree or none is clear, the figure is left out and marked "not included" rather than guessed at.
Before a state is added
A state's sales tax rate and trade-in rule are confirmed before its page goes live. Fees that couldn't be confirmed yet are marked as such rather than left unmentioned, so a reader can see what is and isn't covered.
After publication
- Each state page shows when it was last reviewed.
- Data is re-checked on a regular schedule, and sooner when a change is reported.
- A correction request is checked against an official source before it's published. See corrections.
Independent checks
The calculators are tested against hand-worked examples for every state, not just spot-checked, so a formula error in one state's edge case (a tax cap, a minimum tax, a trade-in exception) gets caught rather than shipped quietly.
How this connects to our methodology
This page sets the bar. Our methodology explains how we actually clear it, source by source.