About

Calculate anything with

Pick a formula, enter the variables you know, leave one blank, click Calculate, and the solver finds your solution in any units, with the algebra and unit conversions shown for reference.

Every formula solver pairs its calculator with a learning zone: what the formula means, where it came from, and how it's used in the field. I built it for students, trades, and the curious experts.

And there is a second half to it now. I believe that quick three-to-five minute interactive lessons can greatly improve a student's understanding and retention — so I built The Exam Room: 727 lessons across 15 courses, Grade 10 through university, where you choose the formula yourself, rearrange it yourself, and place the values and their units yourself. Nothing is solved for you. Practise, track your improvement over time, and compete with your classmates and friends.

How-to →

How the site works: the leave-one-blank trick, units that convert themselves, the calculator, and how the Exam Room scores you. Five minutes and you'll drive it like you built it.

Contact →

Found a bug, a wrong number, or a formula I'm missing? Tell me. I read everything, and the site gets better the day you do.

The story

This site started as an idea in 2011, in a chemical engineering program. I had learned that the fastest way into any course was through its formulas — a formula speaks volumes about the theory behind it. The trouble was the long, multi-step problems: mixed units, surface areas, little carried values, physical constants. They kept ending the same way — a table of classmates, several different answers, and no way to tell whose was right.

I wanted a site that would settle the question. Enter what you know, leave one variable blank, and see the answer with the work shown, so the debate could end and the learning could carry on.

Building it took longer than imagining it. I taught myself HTML, CSS, and PHP from scratch, through online courses, eBooks, formal examples, and a great deal of trial and error, never entirely certain I was headed in the right direction. A first version took shape in 2011, and several more followed, each one sinking into the “now updated” development environments rather than the application I actually wanted to write. Along the way I picked up frameworks, shipped an Android app, then an iOS app — every detour another apprenticeship for this one. The project went cold more than once, set aside for children, for work, for a life's worth of commitments. It never stopped being a passion.

Then, in 2026, building with Claude finally made the coding as fast as the thinking, and a working version came together in under a day, larger than anything I had sketched across fifteen years of imagining it. It will keep growing from here. And here it is, at last: for students, for trades, for anyone curious enough to want the work shown, and for my own kids, who will grow with it.