Calculators

Online calculators handle the arithmetic you would otherwise set up by hand in a spreadsheet: loan repayments, compound interest, percentages, tax, BMI, due dates, and dozens of other everyday figures. Because they run in the browser, there is nothing to install and no template to build.

The ones worth bookmarking show their work. A good calculator states the formula it uses, explains each input, and handles awkward cases such as leap years, rounding, or currency precision rather than quietly getting them wrong. Treat any result that appears without explanation as a starting point to verify, especially for financial or medical decisions.