We compute basic earnings per share (“EPS”) by dividing net income by the weighted average number of common shares outstanding during the period. Diluted EPS is calculated similarly, except that the weighted average outstanding shares are adjusted to include the effects of converting all potentially dilutive share-based awards issued under our employee stock plans. The number of potential common shares outstanding are determined in accordance with the treasury stock method to the extent they are dilutive.

Basic and diluted EPS are calculated using the following weighted average share data (in thousands):

Dilutive potential common shares consist of stock options, restricted stock units and performance units. 

As of December 31, 2020 and 2019, total share-based awards of 270,108 and 280,437, respectively, were excluded from the diluted EPS calculations because their inclusion would have been anti-dilutive.

As of December 31, 2020 and 2019, the number of performance units excluded from the calculation of diluted EPS was 316,445 and 287,287, respectively. Contingently issuable shares with performance conditions are evaluated for inclusion in diluted EPS if, at the end of current period, conditions would be satisfied as if it were the end of the contingency period.