Site Map

The site is organised around one general calculator and a set of pages that each take a single variation of the same mathematics further. The homepage handles the general case: a starting value, a signed rate, and a number of periods, in either discrete or continuous mode. Every page below exists because one specific framing of that formula needs its own variable names, its own defaults, and its own worked example to be useful.

Decay & Half-Life covers the formula running downward, including converting between a periodic decay rate, a continuous decay constant, and a half-life. Growth Models covers the parameters themselves: doubling time, the growth rate, the growth factor, continuous compounding, and the logistic ceiling that bends an unbounded curve into an S-shape.

Population & Biology applies the model to counts of living things, where growth is quoted as a net annual rate, a generation time, or a reproduction number. Finance applies it to money, where the same equation is called compound interest and the inputs gain a compounding frequency and recurring contributions. Math & Reference holds the algebra: every rearrangement of the formula, the logarithm steps that solve for an exponent, the bare exponential function, and least-squares fitting of a curve to measured data.