Exelon (EXC) S-3ASR Automatic shelf registration

EXHIBIT 12.1

Exelon Corporation

	Years Ended December 31,										Six Months Ended June 30, 2007
	2002		2003		2004		2005		2006
Pre-tax income from continuing operations before adjustment for income or loss from equity investees and minority interest	2,693		1,286		2,577		1,895		2,796		2,032
Plus: (Income) or loss from equity investees	(86	)	(33	)	154		134		111		69
Less: Capitalized interest	(28	)	(22	)	(12	)	(15	)	(34	)	(22	)
Preference security dividend requirements of consolidated subsidiaries	(13	)	(7	)	(4	)	(8	)	(7	)	(3	)
Pre-tax income from continuing operations after adjustment for income or loss from equity investees, minority interest, capitalized interest and preference security dividend requirements	2,566		1,224		2,715		2,006		2,866		2,076
Fixed charges:
Interest expensed and capitalized, amortization of debt discount and premium on all indebtness	983		895		841		844		914		449
Interest component of rental expense	167		204		232		277		251		131
Distributions on mandatorily redeemable preferred securities	37		34		—		—		—		—
Preference security dividend requirements of consolidated subsidiaries	13		7		4		8		7		3
Total fixed charges	1,200		1,141		1,077		1,129		1,172		583
Pre-tax income from continuing operations after adjustment for income or loss from equity investees, capitalized interest and preference security dividend requirements plus fixed charges	3,766		2,364		3,792		3,135		4,038		2,659
Ratio of earnings to fixed charges	3.1		2.1		3.5		2.8		3.4		4.6