Exhibit 12.1

Exelon Corporation

Ratio of Earnings to Fixed Charges

	Year Ended December 31,															Nine Months Ended September 30, 2015
($ millions)	2010			2011			2012			2013			2014
Pre-tax income from continuing operations		4,221			3,952			1,798			2,773			2,486			2,767
Plus: Loss from equity investees		—			1			91			(10	)		20			(3	)
Less: Capitalized interest		(43	)		(57	)		(75	)		(67	)		(79	)		(72	)
Pre-tax income from continuing operations after adjustment for income or loss from equity investees and capitalized interest		4,178			3,896			1,814			2,696			2,427			2,692
Fixed Charges:
Interest expensed and capitalized, amortization of debt discount and premium on all indebtedness		836			761			1,021			1,436			1,110			787
Interest component of rental expense (a)		241			237			310			269			288			12
Total fixed charges		1,077			998			1,331			1,705			1,398			799
Pre-tax income from continuing operations after adjustment for income or loss from equity investees and capitalized interest plus fixed charges		5,255			4,894			3,145			4,401			3,825			3,491
Ratio of earnings to fixed charges		4.9			4.9			2.4			2.6			2.7			4.4

(a) Represents one-third of rental expense relating to operating leases, which is a reasonable approximation of the interest factor.