CalcTray is a free library of online calculators for finance, health, math, and everyday decisions. Work out a mortgage payment, loan cost, or compound interest. Check your BMI, BMR, or GPA. Solve geometry. Every calculator runs in your browser with no signup and no download, and shows the steps behind the answer so you can check the math yourself. Prefill the inputs, share a link to your result, or embed a calculator on your own site. Fast on any phone, and ready the moment you land.

This started because I got fed up. Every time I googled something like "mortgage payoff" or "BMR calculator" I'd end up on some page that took moments to load and buried the actual calculator under a wall of ads. And even once it loaded, the layout was such a mess I'd have to hunt around for the one number I actually came for. Then it'd spit out a result with no idea how it got there. So I made CalcTray. It's free, there's no signup, and the answer you want is right there up front, with the math behind it so you can actually check it. Loads fast too since it's just a static site, no tracking junk. Right now there's around 50 of them (mortgage, loans, compound interest, BMI, BMR, GPA, a bunch of geometry ones) and I keep adding more every week. You can prefill the inputs and share a link to your result, which I use constantly. It also saves recent results for a quick cross-comparison. Anyway, would love to know which calculator you actually use most. That's probably what I build next. And if something feels off or broken, tell me, I'd rather hear it.

Love that you can actually see the steps behind each answer instead of just getting a black-box number. The share-by-link and embed features feel like exactly the kind of thing most calculator sites skip over.

CalcTray

Fast, free calculators for money, math, and everyday life

Fast, free calculators for money, math, and everyday life