Net Income per Share Attributable to Common Stockholders

Basic net income per share is computed by dividing net income attributable to common shareholders by the weighted-average number of common shares outstanding during the period. For the three months ended March 31, 2018 and April 1, 2017, we applied the two-class method to calculate basic and diluted net income per share of common stock, as our Series A Redeemable Convertible Preferred Stock (Series A Preferred Stock) is a participating security. The two-class method is an earnings allocated formula that treats a participating security as having rights to earnings that otherwise would have been available to common stockholders. We compute diluted net income per common share using net income as the “control number” in determining whether potential common shares are dilutive, after giving consideration to all potentially dilutive common shares, including stock options, unvested restricted stock outstanding during the period and potential issuance of stock upon the conversion of the our Series A Preferred Stock, including accrued dividends, outstanding during the period, except where the effect of such securities would be antidilutive.

The calculations of basic and diluted net income per share and basic and dilutive weighted-average shares outstanding for the three months ended March 31, 2018 and April 1, 2017 were as follows (in thousands, except per share data):



	Three Months Ended
	March 31, 2018			April 1, 2017
Numerator:
Basic:
Net income attributable to common stockholders	$	1,741		$	192
Dilutive
Net income attributable to common stockholders	$	1,741		$	192
Plus: undistributed earnings allocated to participating securities	956			632
Less: undistributed earnings reallocated to participating securities	(936		)	(630		)
Net income attributable to common stockholders	$	1,761		$	194

Denominator:
Weighted-average shares outstanding - basic	30,551			29,149

Dilutive impact from:
Options outstanding	2,044			1,705
Restricted stock units	749			428
Weighted-average shares outstanding - dilutive	33,344			31,282

Net income per share attributable to common stockholders (Basic)	$	0.06		$	0.01
Net income per share attributable to common stockholders (Diluted)	$	0.05		$	0.01

The following equity shares were excluded from the calculation of diluted net income per share because their effect would have been antidilutive for the periods presented (in thousands):



	Three Months Ended
	March 31, 2018	April 1, 2017
Stock options	954	2,962
Restricted stock units	294	1,391
Series A Redeemable Convertible Preferred Stock (as converted to common stock)	4,851	4,596

The Series A Preferred Stock is considered antidilutive due to the fact that the two-class method was more dilutive when calculating dilutive net income per share attributable to common stockholders.