About Calculus

Calculus is a free Danish website with calculators for math, construction, home, car, energy and finance. The site is run by Tom Frank Christensen.

You can use the calculators for everything from the area of a floor and the amount of paint to electricity use, charging and savings. On the calculator pages, you can read about the assumptions and see examples of when the calculation is useful.

Figures you can work with

A result depends on the information you enter. That is why it must be clear which units and assumptions the calculator uses, and what is included in the result.

Some calculators use fixed mathematical formulas. Others use historical data or assumptions about, for example, consumption, prices and returns. On each page, you can see what the calculation is based on.

Help make the site better

If you find an error, an unclear explanation or a calculator that is missing, you are welcome to contact Tom. Please send a link to the page and the figures you used, so the calculation can be checked.

Read more about Tom at tomc.dk, or go to Contact. You can read how the site handles information under Privacy.