Earnings Per Share

Basic earnings per share (EPS) is calculated using the weighted average number of common shares outstanding during the period and includes the effect of any participating securities as appropriate. Participating securities consist of unvested restricted stock issued to our employees and non-employee directors that provide dividend rights.

Diluted EPS is calculated assuming the issuance of common shares for all potentially dilutive securities, provided the effect is not antidilutive. For all periods presented, our contingent convertible senior notes did not have a dilutive effect and, therefore, were excluded from the calculation of diluted EPS. See Note 3 for further discussion of our convertible senior notes and contingent convertible senior notes.

A reconciliation of basic EPS and diluted EPS for the Current Quarter and the Prior Quarter is as follows:



	Three Months Ended March 31,
	2018		2017
	(in millions, except per share data)
Net income available to common stockholders	$	268	$	75
Effect of dilutive securities	36		—
Diluted income per share	$	304	$	75

Weighted average common and common equivalent shares outstanding - basic	907		906
Effect of dilutive securities	146		1
Weighted average common and common equivalent shares outstanding - diluted	1,053		907

Net income per share attributable to Chesapeake:
Basic	$	0.30	$	0.08
Diluted	$	0.29	$	0.08

Shares of common stock for the following dilutive securities were excluded from the calculation of diluted EPS as the effect was antidilutive:
Common stock equivalent of our preferred stock outstanding	60		60
Common stock equivalent of our convertible senior notes outstanding	—		146
Common stock equivalent of our preferred stock outstanding prior to exchange	—		1
Participating securities	—		1