EXHIBIT 12.1

Corporate Office Properties Trust

Ratio of Earnings to Combined Fixed Charges and Preferred Share Dividends

(Dollars in thousands)

		Six Months Ended June 30, 2017
Earnings:
Income before equity in income of unconsolidated entities and income taxes		$	36,690
Gain on sales of real estate		4,250
Combined fixed charges and preferred share dividends (from below)		48,181
Amortization of capitalized interest		1,301
Distributed income of equity investees		750
Subtract:
Capitalized interest (from below)		(3,142		)
Preferred share dividends included in fixed charges		(6,219		)
Preferred unit distributions included in fixed charges		(330		)
Preferred distributions of other consolidated entities		(8		)
Total earnings		$	81,473
Combined Fixed Charges and Preferred Share Dividends:
Combined fixed charges and preferred share dividends:
Interest expense		$	38,157
Capitalized interest (internal and external)		3,142
Interest included in rental expense		325
Preferred share dividends		6,219
Preferred unit distributions		330
Preferred distributions of other consolidated entities		8
Total combined fixed charges and preferred share dividends		$	48,181
Ratio of earnings to combined fixed charges and preferred share dividends		1.69

For purposes of calculating the above ratios, earnings were computed by adding fixed charges (excluding capitalized interest), gain on sales of real estate (excluding discontinued operations) amortization of capitalized interest and distributed income of equity investees to income before noncontrolling interests, equity in income of unconsolidated entities and income taxes. Fixed charges consist of interest costs and capitalized amortization of debt issuance costs.