How it's calculated
CAGR = (End ÷ Start)^(1 ÷ t) − 1
t is the number of years and may include a fraction. The starting value must be above 0, because growth from nothing has no rate.
Assumptions
- Growth is treated as if it compounded evenly every year.
- No money was added or taken out during the period.
Worked example
A value that grows from 10,000 to 20,000 in 5 years has a CAGR of about 14.87% a year, even though it doubled in total.
Questions
Why is CAGR lower than total growth divided by the years?
Because growth compounds. Doubling in 5 years is 100% in total, but only about 14.87% a year once each year builds on the last.
Can CAGR be negative?
Yes. If the ending value is lower than the starting value, the rate is negative. An ending value of 0 gives −100%.
What if I added money along the way?
CAGR assumes a single starting amount. With regular additions, a money-weighted measure such as XIRR is more suitable.