Calculators are Cooking!
Bit by bit, I'm optimizing my calculators. These popular pages help students and others around the world every day. The one above gives handy conversions for measures used in cooking (and there's a lot more of that, these days). And there are ones for exponents (incredibly popular) and roots and BMI (all that cooking) and even numerology. Things cross-pollinate, and the numerology calculator was the inspiration for The Numerology Machine in my first novel, TIME AERIALS.
It all began, this calculator thing, when I wanted to check the diameter of model viral cores based on genome length. Trying to do all those circle and sphere equations (sometimes in reverse) got a bit much, so I wrote a circle-sphere calculator:
...where you can happily work out results from all starting points. For example, you can get the diameter of a sphere if you know its volume. I bet there's something of interest for you there, so have a look!