CFLib.org – Common Function Library Project

Description:
Calculates Internal Rate of Return (IRR) similar to excel IRR function.

Return Values:
Returns a numeric value.

Example:

<cfscript>
    cFlow = arrayNew(1);
    cFlow[1] = -4000;
    cFlow[2] = 1200;
    cFlow[3] = 1410;
    cFlow[4] = 1875;
    cFlow[5] = 1050;
    
    myIRR = calcIRR(cFlow);
 </cfscript>    

 <cfdump var="#cFlow#">
 <cfoutput>irr = #myIRR#</cfoutput>

Parameters:

Full UDF Source:

<!---
 Calculate IRR.
 
 @param arrCashFlow      Array of cashflow. (Required)
 @return Returns a numeric value. 
 @author CF Ninja (coldfusion.ninja@hotmail.com) 
 @version 1, November 13, 2014 
--->
<cffunction name="calcIRR" output="false">
    <cfargument name="arrCashFlow" type="Array" required="yes" hint="array of cashflow">
    <cfscript>
        var guess = 0.1;
        var inc   = 0.00001;
        do {
            guess += inc;
            npv = 0; //net present value
            for (var i=1; i<=arrayLen(arguments.arrCashFlow); i++)    {
                npv += arguments.arrCashFlow[i] / ((1 + guess) ^ i);    
            }
            
        } while ( npv > 0 );
        
        guess =  guess * 100;
    </cfscript>
    <cfreturn guess>
</cffunction>