Finance math you can actually verify
Free calculators for loans, taxes, investments, and everyday money decisions. Every tool keeps your numbers on your device and shows how the answer is built.
697
Calculators
100%
Free to use
0
Inputs stored
Private by design
Every calculator runs in your browser. Inputs are never sent to a server.
Transparent math
Formulas are shown step-by-step with links to independent references.
Shareable scenarios
Encode inputs in the URL to compare loan or tax scenarios with someone else.
Fresh additions
Recently added calculators
NewThe latest additions and updated calculation models in our toolkit.
Knowledge & Research
Financial guides & insights
Deep-dive formula breakdowns, mathematical derivations, and actionable financial guides.
Frequently asked questions
Are these calculators free to use?
Yes. Every calculator on Finance Tools is free, with no account, credits, or paywall.
Do I need to create an account?
No. Open a calculator and start entering numbers. Nothing here requires registration.
Are my inputs private?
Yes. Math runs on your device. We do not store, view, or log the numbers you enter.
How accurate are the results?
Each tool shows the formula it uses and cites independent references. Results are estimates — verify anything you will use for a legal, tax, or lending decision.
Do the calculators work on a phone?
Yes. The layout is built for phones, tablets, and desktops, and most tools work even if you go offline after the page loads.