Exhibit 12.1

Exelon Corporation

Ratio of Earnings to Fixed Charges

		Year Ended December 31,
($ millions)		2011				2012				2013				2014				2015
Pre-tax income from continuing operations			3,952				1,798				2,773				2,486				3,330
Plus: Loss from equity investees			1				91				(10	)			20				—
Less: Capitalized interest			(57	)			(75	)			(67	)			(79	)			(99	)
Pre-tax income from continuing operations after adjustment for income or loss from equity investees and capitalized interest			3,896				1,814				2,696				2,427				3,231
Fixed Charges:
Interest expensed and capitalized, amortization of debt discount and premium on all indebtedness			761				1,021				1,436				1,110				1,107
Interest component of rental expense (a)			237				310				269				288				300
Total fixed charges			998				1,331				1,705				1,398				1,407
Pre-tax income from continuing operations after adjustment for income or loss from equity investees and capitalized interest plus fixed charges			4,894				3,145				4,401				3,825				4,638
Ratio of earnings to fixed charges			4.9				2.4				2.6				2.7				3.3

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