About DailyCalc

DailyCalc is a collection of 51 calculators covering the questions that come up in ordinary life: what a loan really costs, how many calories to eat, what a plot of land measures in square feet, how long a download will take.

Everything runs in your browser

There is no back end. Every formula executes as JavaScript on your own device, which means the numbers you enter — income, weight, medical dates, loan balances — are never transmitted to a server, never logged, and never stored. Closing the tab discards them.

How the maths is verified

Each calculator is built on a shared library of pure functions, and that library is covered by an automated test suite that checks known results, boundary conditions and invalid input. The same engine also powers the DailyCalc Android app, so a figure calculated here matches the one calculated there.

What these tools are not

They are estimates, and estimates rest on assumptions. A retirement projection cannot know what markets will do; a BMI figure cannot see your body composition; a due date is a probability, not an appointment. Nothing here is financial, medical, legal or engineering advice, and decisions that matter deserve a qualified professional as well as a calculator.

Corrections

If a result looks wrong, it may well be. Formula corrections are welcome and get fixed quickly — accuracy is the entire value of a site like this.