Alterra Capital 10-Q 2011 Q2 Quarterly report

											Exhibit 12.1
COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
(Expressed in thousands of U.S. Dollars, except ratios)	Six Months Ended June 30, 2011			Year End December 31, 2010		Year End December 31, 2009		Year End December 31, 2008			Year End December 31, 2007		Year End December 31, 2006
Earnings:
Pre-tax income (loss) before income (loss) from equity investees	$	20,921		$	305,891	$	256,236	$	(174,086	)	$	302,827	$	217,988
Fixed charges		20,267			30,556		23,260		37,462			43,562		14,503
Total (Loss) Earnings	$	(654	)	$	336,447	$	279,496	$	(136,624	)	$	346,389	$	232,491
Fixed Charges:
Interest and amortization on indebtedness	$	19,114			28,467		21,453		36,143			42,702		13,832
Rental expense at 33.3% (1)		1,153			2,089		1,807		1,319			860		671
Total Fixed Charges	$	20,267		$	30,556	$	23,260	$	37,462		$	43,562	$	14,503
Ratio of Earnings to Fixed Charges		(0.03	)		11.0		12.0		(3.7	)		8.0		16.0
Deficiency	$	(20,921	)		N/A		N/A	$	(174,086	)		N/A		N/A

(1) 33.3% represents a reasonable approximation of the interest factor