Investment Return Calculator

"What return did I make?" can mean different things depending on what you're asking. A simple return just compares a starting and ending value. An annualised return (CAGR) expresses that same change as a steady yearly rate, which is what makes it possible to fairly compare a two-year investment against a ten-year one. Neither of those is the same question as "what did I gain compared to what I actually paid in?" once you're adding money regularly rather than investing a single lump sum.

Why contributions change the maths

CAGR assumes a single amount invested at the start and left untouched. Once you're contributing £200 a month, each contribution has been invested for a different length of time, so there's no single accurate annualised percentage without a proper money-weighted calculation (like XIRR). Rather than present a misleading annualised figure, the contributions mode here shows your total gain as a percentage of what you actually put in.