Determine the total earnings for the period
Determine the amount invested or starting capital
Subtract the starting capital from the total earnings to get net earnings
Divide net earnings by the starting capital
Multiply the result by 100 to get the return percentage
Formula: Return of Earnings = [(Total Earnings – Starting Capital) / Starting Capital] × 100
If needed, include additional income and subtract related costs before calculating the percentage
Use the same time period for all values being compared