Exhibit 12

Arch Capital Group Ltd. and Subsidiaries

Computation of Ratio of Earnings to Fixed Charges and Preference Dividends

(in thousands, except ratios)

	Years Ended December 31,
	2012			2011		2010			2009			2008
Income before income taxes	$	589,387		$	426,370	$	850,401		$	890,802		$	304,442
Equity in net (income) loss of investees	(43,632		)	71,100		(56,035		)	(183,038		)	166,326
Fixed charges	34,223			37,166		35,018			30,074			29,673
Income available for fixed charges	$	579,978		$	534,636	$	829,384		$	737,838		$	500,441
Fixed charges:
Interest and amortization on indebtedness	28,525			31,691		30,007			24,440			23,838
Estimate of interest component within rental expense net of sublease (income) (1)	5,698			5,475		5,011			5,634			5,835
Total fixed charges	34,223			37,166		35,018			30,074			29,673
Preference dividends	25,079			25,844		25,844			25,844			25,844
Total fixed charges and preference dividends	59,302			63,010		60,862			55,918			55,517
Ratio of earnings to fixed charges	16.9			14.4		23.7			24.5			16.9
Ratio of earnings to fixed charges and preference dividends	9.8			8.5		13.6			13.2			9.0

(1)  Represents a reasonable approximation of the interest cost component of rental expense net of sublease (income) incurred by the Company.