By calculating a company's weighted average number of outstanding shares, we can get a more accurate picture of its earnings.

To calculate the average percentage difference over time, you'll need to build a time series of data. The starting point is the price information for each date on which you're producing an average.

The article How to Calculate a Company's Weighted Average Number of Outstanding Shares originally appeared on Fool.com. Try any of our Foolish newsletter services free for 30 days .

How to use the average percentage difference The meaning of the average percentage difference depends on the nature of the two numbers involved in the calculation.