Earnings per Share

Basic earnings per share excludes the dilutive effects of stock options, restricted stock units (RSUs), and the nil coupon non-redeemable convertible unsecured loan notes. Diluted earnings per share includes the dilutive effect of the nil coupon non-redeemable convertible unsecured loan notes, RSUs, and unexercised in-the-money stock options, except in periods of net loss where the effect of these instruments is anti-dilutive. Out-of-money stock options are excluded from diluted earnings per share because they are anti-dilutive. For the three and nine months ended September 30, 2019 and for the nine months ended September 30, 2018, basic earnings per share is equal to diluted earnings per share because all outstanding stock awards and convertible loan notes are considered anti-dilutive during periods of net loss. For the three months ended September 30, 2018, diluted earnings per share includes unexercised options and unvested RSUs since net income was generated in that period and the effect of those instruments is dilutive. The following table sets forth the weighted-average shares used in calculating the earnings per share for the three and nine months ended September 30, 2019 and 2018.



	Three Months Ended September 30,		Nine Months Ended September 30,
	2019	2018	2019	2018
Basic weighted-average shares	24,187,000	24,171,000	24,183,000	24,162,000
Conversion of unsecured loan notes	—	—	—	—
Unexercised options and unvested RSUs	—	417,000	—	—
Diluted weighted-average shares	24,187,000	24,588,000	24,183,000	24,162,000

Fuel Tech had 1,269,000 and 1,286,000 weighted average equity awards outstanding at September 30, 2019 and 2018, respectively, that were not dilutive for the purposes of inclusion in the calculation of diluted earnings per share but could potentially become dilutive in future periods.