Rate of return
From ACT Wiki
The investor's return on an investment expressed as a proportion of the amount invested.
Most commonly expressed as a percentage.
Example
GBP 1 million is invested.
GBP 1.03 million is repayable at the end of the period.
The periodic rate of return (r) is:
r = (End amount / Start amount) - 1
Which can also be expressed as:
r = (End / Start) - 1
or
r = <math>\frac{End}{Start}</math> - 1
= <math>\frac{1.03}{1}</math> - 1
= 0.03
= 3%