Exhibit 12.1

Exelon Corporation

Ratio of Earnings to Fixed Charges

	2009			2010			2011			2012			2013			3 Months Ended March 31, 2014
Pre-tax income from continuing operations		4,418			4,221			3,952			1,798			2,773			39
Plus: Loss from equity investees		27			—			1			91			(10	)		19
Less: Capitalized interest		(55	)		(43	)		(57	)		(75	)		(67	)		(20	)
Pre-tax income from continuing operations after adjustment for income or loss from equity investees and capitalized interest		4,390			4,178			3,896			1,814			2,696			38
Fixed Charges:
Interest expensed and capitalized, amortization of debt discount and premium on all indebtedness		761			836			761			1,055			1,470			256
Interest component of rental expense (a)		230			241			237			310			269			76
Total fixed charges		991			1,077			998			1,331			1,705			332
Pre-tax income from continuing operations after adjustment for income or loss from equity investees and capitalized interest plus fixed charges		5,381			5,255			4,894			3,145			4,401			370
Ratio of earnings to fixed charges		5.4			4.9			4.9			2.3			2.6			1.1

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

Exelon Corporation

Ratio of Earnings to Fixed Charges and Preferred Stock Dividends

	2009			2010			2011			2012			2013			3 Months Ended March 31, 2014
Pre-tax income from continuing operations		4,418			4,221			3,952			1,798			2,773			39
Plus: Loss from equity investees		27			—			1			91			(10	)		19
Less: Capitalized interest		(55	)		(43	)		(57	)		(75	)		(67	)		(20	)
Preference security dividend requirements		(7	)		(7	)		(6	)		(26	)		(32	)		(1	)
Pre-tax income from continuing operations after adjustment for income or loss from equity investees, capitalized interest and preference security dividend requirements		4,383			4,171			3,890			1,788			2,664			37
Fixed Charges:
Interest expensed and capitalized, amortization of debt discount and premium on all indebtedness		761			836			761			1,055			1,470			256
Interest component of rental expense (a)		230			241			237			310			269			76
Preference security dividend requirements of consolidated subsidiaries		7			7			6			26			32			1
Total fixed charges		998			1,084			1,004			1,357			1,737			333
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		5,381			5,255			4,894			3,145			4,401			370
Ratio of earnings to fixed charges and preferred stock dividends		5.4			4.8			4.9			2.3			2.5			1.1

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