Apple numbers User Manual

    Dictionary of Functions 

 

The IRR function calculates the internal rate of return for an investment that is based on 
a series of potentially irregular cash flows rather than fixed-interest income. The rate 
returned is the rate that makes the net present value of a series of cash flows 0.

IRR(flows-range, [estimate])

 flows-range:  A range of cells that contain cash flow values. Positive values represent 

income. Negative values represent expenditures. All values must represent equal 
time intervals.

 estimate:  Optional; an initial estimate for the rate of return. If omitted, 10% is used. 

Try adjusting the estimate if IRR fails to return a result.

  

The ISBLANK function returns TRUE if the specified cell is empty and FALSE otherwise.

ISBLANK(cell)

 cell:  A reference to a table cell.

  

If cells A1:F1 contain -1000, 50, 50, 50, 50, 1050: 
  

IRR(A1:F1) returns 5%, the rate of return if you invest $1,000 and receive $50 per year for 4 years and a 
final payment of $1,050 in the fifth year.

To find the rate of return if you pay $20,000 for a machine, run the machine for 5 years generating 
$8,000 per year, and then sell the machine at the end of the fifth year for $2,000, enter -20000, 8000, 
8000, 8000, 8000, 10000 in cells A1:A6 and use the formula IRR(A1:A6). The value 30.06% is returned.

Given the following table: 
  

ISBLANK(A1) returns TRUE.

ISBLANK(B2) returns FALSE.