5. Net Loss Attributable to ORBCOMM Inc. Common Stockholders

The Company accounts for earnings per share (“EPS”) in accordance with ASC Topic 260, “Earnings Per Share” (“ASC 260”) and related guidance, which requires two calculations of EPS to be disclosed: basic and diluted. The numerator in calculating basic and diluted EPS is an amount equal to the net loss attributable to ORBCOMM Inc. common stockholders for the periods presented. The denominator in calculating basic EPS is the weighted average shares outstanding for the respective periods. The denominator in calculating diluted EPS is the weighted average shares outstanding, plus the dilutive effect of stock option grants, unvested SAR and RSU grants and shares of Series A convertible preferred stock, for the respective periods. The following sets forth the basic and diluted calculations of EPS for the quarters and six months ended June 30, 2018 and 2017:

	Quarters Ended						Six Months Ended
	June 30,						June 30,
	2018			2017			2018			2017
Net loss attributable to ORBCOMM Inc. common stockholders	$	(7,233	)	$	(10,740	)	$	(17,319	)	$	(14,083	)
Weighted average number of common shares outstanding:
Basic number of common shares outstanding		78,079			71,978			76,404			71,703
Dilutive effect of unvested SARs and RSUs and shares of Series A convertible preferred stock		—			—			—			—
Diluted number of common shares outstanding		78,079			71,978			76,404			71,703
Earnings per share:
Basic	$	(0.09	)	$	(0.15	)	$	(0.23	)	$	(0.20	)
Diluted	$	(0.09	)	$	(0.15	)	$	(0.23	)	$	(0.20	)

The computation of net loss attributable to ORBCOMM Inc. common stockholders for the quarters and six months ended June 30, 2018 and 2017 is as follows:

	Quarters Ended						Six Months Ended
	June 30,						June 30,
	2018			2017			2018			2017
Net loss attributable to ORBCOMM Inc.	$	(7,222	)	$	(10,740	)	$	(17,308	)	$	(14,083	)
Preferred stock dividends on Series A convertible preferred stock		(11	)		—			(11	)		—
Net loss attributable to ORBCOMM Inc. common stockholders	$	(7,233	)	$	(10,740	)	$	(17,319	)	$	(14,083	)