About CalculatorByState

What this site is

CalculatorByState is an independent site with 47 free financial calculators across 8 categories — mortgage, insurance, investment, retirement, loans, budget, salary and rent — built around one idea: the number that matters is the all-in cost in your state, not a national average. Property tax, homeowners insurance, transfer tax, income tax brackets, security-deposit law and sales-tax treatment of a car all vary by state, and every calculator here reads the figures for the state you pick.

Alongside the calculators are 433 articles, including a researched guide per state for the biggest decisions — buying a home, closing costs, take-home pay, renting, home insurance, retiring, and owning a rental — each written for that state's rules rather than adapted from a template.

Who makes it

The site is built, researched and maintained by Korbin S. Every article carries that byline and the date it was last updated. The calculators are deterministic — the same inputs always produce the same output, with no AI in the math — and the formulas behind them are written up, with their sources, on the methodology page.

Where the numbers come from

Every state-level figure — a property tax rate, an average premium, a transfer-tax rule, an income-tax bracket — is stored with the source it was taken from and the date it was checked, for all 50 states. Switch any calculator to Expert mode to see the citation under each figure. When a state changes a rule, the figure is updated at the source and the date moves with it; nothing is hand-edited into a page.

If you find a figure that is out of date or wrong, please tell us — a correction with a link to the official source is the most useful message this site receives.

How it is paid for, and what it will never do

The calculators and articles are free and supported by display advertising, plus optional paid guides, templates and an All-Access subscription. None of that touches the math: an ad never appears inside a calculator's form or result, and the site does not run lead forms, does not route anyone to a lender, insurer or agent, and does not sell or pass on anything you type into a calculator. That pledge is written up on the methodology page and backed by the privacy policy.

Contact

korbin@kobindesign.com — or see the contact page for what to include with a correction.