EXHIBIT 12.1

BOSTON PROPERTIES LIMITED PARTNERSHIP

CALCULATION OF RATIOS OF EARNINGS TO FIXED CHARGES

CALCULATION OF RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND

PREFERRED DISTRIBUTIONS

Boston Properties Limited Partnership’s ratios of earnings to fixed charges and ratios of earnings to combined fixed charges and preferred distributions for the nine months ended September 30, 2012 and the five years ended December 31, 2011 were as follows:

	Nine Months Ended September 30, 2012			Year Ended December 31,
				2011			2010			2009			2008			2007
	(dollars in thousands)
Earnings:
Add:
Income from continuing operations before income (loss) from unconsolidated joint ventures	$	183,301		$	236,153		$	159,042		$	258,904		$	287,426		$	344,156
Gains on sales of real estate		—			—			2,734			11,760			33,340			957,406
Amortization of interest capitalized		3,935			4,188			2,660			2,498			2,315			2,394
Distributions from unconsolidated joint ventures		13,760			22,451			10,733			6,676			5,988			7,157
Fixed charges (see below)		339,577			442,309			419,060			371,649			341,608			336,302
Subtract:
Interest capitalized		(31,409	)		(48,178	)		(40,981	)		(48,816	)		(46,286	)		(33,322	)
Total earnings	$	509,164		$	656,923		$	553,248		$	602,671		$	624,391		$	1,614,093
Fixed charges:
Interest expensed	$	308,168		$	394,131		$	378,079		$	322,833		$	295,322		$	302,980
Interest capitalized		31,409			48,178			40,981			48,816			46,286			33,322
Total fixed charges	$	339,577		$	442,309		$	419,060		$	371,649		$	341,608		$	336,302
Preferred distributions		2,440			3,339			3,343			3,594			4,226			10,429
Total combined fixed charges and preferred distributions	$	342,017		$	445,648		$	422,403		$	375,243		$	345,834		$	346,731
Ratio of earnings to fixed charges		1.50			1.49			1.32			1.62			1.83			4.80
Ratio of earnings to combined fixed charges and preferred distributions		1.49			1.47			1.31			1.61			1.81			4.66