EXHIBIT 12.1

BOSTON PROPERTIES, INC.

CALCULATION OF RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED DISTRIBUTIONS

Boston Properties, Inc.'s ratios of earnings to combined fixed charges and preferred distributions for the nine months ended September 30, 2005 and the five years ended December 31, 2004 were as follows:

	Nine Months Ended September 30, 2005			Year Ended December 31,
				2004			2003			2002			2001			2000
	(dollars in thousands)
Earnings:
Add:
Income before minority interests in property partnerships, income from unconsolidated joint ventures, minority interest in Operating Partnership, gains (losses) on sales of real estate and other assets and land held for development, discontinued operations, cumulative effect of a change in accounting principle and preferred dividend	$	222,726		$	307,399		$	294,353		$	270,913		$	239,498		$	204,538
Gains (losses) on sales of real estate and land held for development		124,368			9,822			70,244			232,304			11,238			(313	)
Amortization of interest capitalized		2,471			2,845			2,640			2,526			950			415
Distributions from unconsolidated joint ventures		3,867			6,663			8,412			8,692			2,735			1,848
Combined fixed charges and preferred distributions (see below)		259,858			334,082			342,244			316,835			306,709			275,607
Subtract:
Interest capitalized		(3,293	)		(10,849	)		(19,200	)		(22,510	)		(59,292	)		(37,713	)
Preferred distributions		(23,278	)		(17,063	)		(23,608	)		(31,258	)		(36,026	)		(32,994	)
Total earnings	$	586,719		$	632,899		$	675,085		$	777,502		$	465,812		$	411,388
Combined fixed charges and preferred distributions:
Interest expensed	$	233,287		$	306,170		$	299,436		$	263,067		$	211,391		$	204,900
Interest capitalized		3,293			10,849			19,200			22,510			59,292			37,713
Preferred distributions		23,278			17,063			23,608			31,258			36,026			32,994
Total combined fixed charges and preferred distributions	$	259,858		$	334,082		$	342,244		$	316,835		$	306,709		$	275,607
Ratio of earnings to combined fixed charges and preferred distributions		2.26			1.89			1.97			2.45			1.52			1.49

The ratio of earnings to combined fixed charges and preferred distributions was computed by dividing earnings by combined fixed charges and preferred distributions. Earnings consist of income before minority interests in property partnerships, income from unconsolidated joint ventures, minority interest in Operating Partnership, discontinued operations, cumulative effect of a change in accounting principle and preferred dividend, plus amortization of interest capitalized, distributions from unconsolidated joint ventures, and combined fixed charges and preferred distributions, minus interest capitalized and preferred distributions. Combined fixed charges and preferred distributions consist of interest expensed, which includes credit enhancement fees and amortization of loan costs, interest capitalized, and preferred distributions.