The Calc Library

About The Calc Library

The Calc Library is a free collection of online calculators covering personal finance, health and fitness, selling on marketplaces, printables, everyday math, and science and engineering. It is aimed at shoppers and small sellers who want a quick answer, as well as students and anyone checking a number by hand.

Each calculator shows the formula behind its result, so users can check the working rather than trust a black box. Examples include a loan and EMI calculator with an amortization schedule, an Etsy fee breakdown, and gross and net profit margin tools that separate markup from margin. There is no sign-up, no paywall and nothing to install.

According to the site, calculations run in the browser on the user's device and are not sent to a server. The library is organised into category hubs with a search bar and a full index, which makes it easy to move from a general question to a specific calculator.