4. Earnings per Share

Basic earnings per common share amounts are calculated using the weighted average number of common shares outstanding for the period. Diluted earnings per common share amounts are calculated using the weighted average number of common shares outstanding plus the additional dilution for all potentially dilutive securities, such as nonvested restricted stock. During loss periods, diluted loss per share amounts are based on the weighted average number of common shares outstanding, because the inclusion of common stock equivalents would be antidilutive.

The dilutive effect of stock-based compensation arrangements is accounted for using the treasury stock method. The Company includes as assumed proceeds the amount of compensation cost attributed to future services and not yet recognized. For the twenty-six weeks ended August 4, 2018 and July 29, 2017, there were 118,000 and 144,000 shares of nonvested restricted stock, respectively, excluded from the calculation of diluted earnings per share because of antidilution. For the thirteen weeks ended August 4, 2018 and July 29, 2017, there were 127,000 and 178,000 shares of nonvested restricted stock, respectively, excluded from the calculation of diluted earnings per share because of antidilution.

The following table provides a reconciliation of the average number of common shares outstanding used to calculate basic earnings per share to the number of common shares and common stock equivalents outstanding used in calculating diluted earnings per share for the twenty-six and thirteen week periods ended August 4, 2018 and July 29, 2017:


	Twenty-Six Weeks Ended
	August 4, 2018	July 29, 2017
Average number of common shares outstanding	13,446,285	14,550,435
Incremental shares from assumed vesting of nonvested restricted stock	45,009	47,990
Average number of common shares and common stock equivalents outstanding	13,491,294	14,598,425


	Thirteen Weeks Ended
	August 4, 2018	July 29, 2017
Average number of common shares outstanding	13,314,470	14,381,738
Incremental shares from assumed vesting of nonvested restricted stock	36,851	—
Average number of common shares and common stock equivalents outstanding	13,351,321	14,381,738