CAGR (compound annual growth rate)
The steady yearly rate that gets from start to end value.
CAGR is the single yearly growth rate that would turn a starting value into an ending value over a period, smoothing out the ups and downs in between.
Why use it
Real returns jump around from year to year. CAGR gives you one comparable number, so you can line up investments or periods of different lengths.
For plans with regular contributions, a money-weighted return is the fairer measure, since money goes in at different times. FatDCA calculators show that as "per year".
Example$10,000 that grows to $20,000 over 10 years has a CAGR of about 7.2%.