What RRI does
RRI finds the steady compound growth rate that connects a starting value to an ending value over a given number of periods. When your periods are years, the result is a compound annual growth rate (CAGR). When your periods are months, the result is a monthly rate.
The calculation is equivalent to (fv/pv)^(1/nper)-1. It uses only the endpoints and elapsed periods, so it doesn't tell you how much the value changed in each intervening period.
Practical examples
Find annual revenue growth over five years
Suppose annual revenue rises from $100,000 in 2021 to $161,051 in 2026. Enter these inputs:
| Cell | Meaning | Value |
|---|---|---|
| B2 | Starting revenue | 100000 |
| B3 | Ending revenue | 161051 |
| B4 | Elapsed years | 5 |
Enter this formula in B5:
=RRI(B4,B2,B3)
The result is 0.1, displayed as 10% with Percentage formatting. You can check it by calculating 100000*1.1^5, which gives 161051.
There are six year labels from 2021 through 2026, but five intervals between them. Use those five intervals for nper. The CAGR walkthrough shows the full annual table and the equivalent exponent formula.
Measure an annual decline between two positive values
Suppose an investment falls from $1,000 to $729 over three years, with no money added or withdrawn:
=RRI(3,1000,729)
The result is −0.1, displayed as −10%. A constant 10% annual decline takes the value from 1000 to 900, then 810, then 729. Both endpoints remain positive; the negative result describes the direction of the change.
Common mistakes and notes
Match the rate to the period count
RRI doesn't choose a time unit for you. A count of years produces a yearly rate; a count of months produces a monthly rate. Use comparable beginning and ending measurements and count the elapsed intervals, not the number of rows in your table.
Format the result without multiplying it by 100
A result of 0.1 already represents 10%. Apply Percentage formatting to see it that way. Multiplying by 100 and then applying Percentage formatting would display 1000%.
Check the inputs before interpreting errors
For the conventional growth calculations shown here, use positive starting and ending values and a positive period count. Zero or negative endpoints need separate interpretation; don't treat them as ordinary CAGR inputs.
Microsoft documents #NUM! for invalid argument values and #VALUE! for invalid data types. Check that all three arguments contain numbers and that the period count describes a real span. Microsoft's general error notes do not enumerate every invalid numeric combination.
Keep cash flows and annual changes in view
RRI has no argument for deposits or withdrawals. If you use it to measure an investment's growth, adding money during the period changes the balance without necessarily representing investment earnings. Also, a steady rate returned by RRI doesn't mean that every year's actual change matched that rate.