Earnings per Share

12 Months Ended

Dec. 31, 2015

12. Earnings per share of QTS Realty Trust, Inc.

Basic income (loss) per share is calculated by dividing the net income (loss) attributable to common shares by the weighted average number of common shares outstanding during the period. Diluted income (loss) per share adjusts basic income (loss) per share for the effects of potentially dilutive common shares.

The computation of basic and diluted net income per share is as follows (in thousands, except per share data):


	Year Ended		For the period October 15, 2013
	December 31,		through
	2015	2014	December 31, 2013
Numerator:
Net income available to common stockholders - basic	$ 20,326	$ 15,072	$ 3,154
Effect of net income attributable to noncontrolling interests	3,803	4,031	848
Net income available to common stockholders - diluted	$ 24,129	$ 19,103	$ 4,002
Denominator:
Weighted average shares outstanding - basic	37,568	29,055	28,973
Effect of Class A and Class RS partnership units *	7,029	7,770	7,797
Effect of Class O units and options to purchase Class A common stock on an "as if" converted basis *	756	309	24
Weighted average shares outstanding - diluted	45,353	37,134	36,794

Net income per share attributable to common stockholders - basic	$ 0.54	$ 0.52	$ 0.11
Net income per share attributable to common stockholders - diluted	$ 0.53	$ 0.51	$ 0.11

The Class A units, Class RS units and Class O units represent limited partnership interests in the Operating Partnership, and are described in more detail in Note 8.

The computation of diluted net income per share for the period ended December 31, 2013 does not include 1,113,169 Class O units with an exercise price of $25.00 as their inclusion would have been antidilutive for that period. No securities were antidilutive for the years ended December 31, 2014 and 2015, and as such, no securities were excluded from the computation of diluted net income per share for those periods.