Presented below is a summary of the components used to calculate basic and diluted income per share. The Company applies the two-class method of computing income per share, as nonvested share-based awards that contain nonforfeitable rights to dividends are considered securities which participate in undistributed earnings with common stock. The two-class method requires the calculation of separate income per share amounts for the nonvested share-based awards and for common stock. Income per share attributable to common stock is shown in the table below. Nonvested share-based awards are further discussed in Note 12.



	For the Three Months Ended March 31
(In thousands, except per share data)	2013		2012
Basic income per common share:
Net income attributable to Commerce Bancshares, Inc.	$	61,017	$	65,799
Less income allocated to nonvested restricted stockholders	594		562
Net income available to common stockholders	$	60,423	$	65,237
Weighted average common shares outstanding	90,211		92,632
Basic income per common share	$	.67	$	.70
Diluted income per common share:
Net income attributable to Commerce Bancshares, Inc.	$	61,017	$	65,799
Less income allocated to nonvested restricted stockholders	593		561
Net income available to common stockholders	$	60,424	$	65,238
Weighted average common shares outstanding	90,211		92,632
Net effect of the assumed exercise of stock-based awards - based on
the treasury stock method using the average market price for the respective periods	233		352
Weighted average diluted common shares outstanding	90,444		92,984
Diluted income per common share	$	.67	$	.70