Calculators

CALCULATORS Many scientific and mathematical calculators, ranging from circle and sphere equations to house prices. Originally written to make my own life easier, they have evolved into a popular resource used by people all over the world. I have optimised them for mobile devices, so you can play with them on the go.

The circle sphere calculator goes from any starting point, so if you know, say, the surface area of a sphere, then you can calculate its radius. I originally wrote it to estimate the size of viral cores...

The house price calculator is a quick way to budget for investment properties. You can work out what rent you need to charge to make a profit...

The hourly rate calculator is a quick way for freelancers to work out an hourly rate to charge. Those on a salary can work out their equivalent hourly rate...

And then, for fun, try the numerology calculator with Pythagorean, Chaldean, and (invented by me) pi letter-to-number maps. This calculator inspired the chapter The Numerology Machine in my book Time Aerials. In this story, the universe ties itself in knots trying to make destinies match names...