CalcTools is a free collection of online calculators and unit converters built for everyday use. Our mission is simple: give everyone access to accurate, fast, and easy-to-use calculation tools — with no sign-up, no fees, and no data collection.
We build free web-based calculators that help people with common everyday calculations — from working out their take-home salary and calculating VAT on invoices, to converting weights and temperatures, planning loan repayments, and generating secure passwords.
Every tool on CalcTools runs entirely in your browser. No data you enter is ever sent to our servers, stored, or shared. What you calculate stays on your device.
Our calculators are used by employees checking salary offers, freelancers calculating VAT on invoices, students learning about compound interest, travellers converting units, and anyone who needs a quick, reliable answer to a number question.
We currently offer 10 free calculators and converters:
CalcTools is designed for informational and estimation purposes. While we use standard formulas and strive for accuracy, results should not be used as the sole basis for legal, financial, medical, or other professional decisions.
Tax rates, social contribution rates, and financial regulations vary by country, region, and individual circumstances. Always verify important calculations with a qualified professional or official source.