EXHIBIT 12.1 SENIOR HOUSING PROPERTIES TRUST COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES (Dollars in thousands) Year Ended December 31, ------------------------------------------------------------------------ 2000 1999 1998 1997 1996 ------------------------------------------------------------------------ Earnings: Income before gain on sale of properties $31,022 $14,834 $46,236 $44,723 $36,441 Fixed charges 15,366 18,768 19,293 16,958 14,719 ------------------------------------------------------------------------ Adjusted Earnings $46,388 $33,602 $65,529 $61,681 $51,160 ======================================================================== Fixed Charges: Interest expense $15,366 $18,768 $19,293 $16,958 $14,719 ------------------------------------------------------------------------ Total Fixed Charges $15,366 $18,768 $19,293 $16,958 $14,719 ======================================================================== Ratio of Earnings to Fixed Charges 3.0x 1.8x 3.4x 3.6x 3.5x ======================================================================== Senior Housing Properties Trust ("Senior Housing"), was organized on December 16, 1998, as a 100% owned subsidiary of HRPT Properties Trust ("HRPT"). On October 12, 1999, HRPT distributed 50.7% of its ownership in Senior Housing to HRPT shareholders (the "Spin-Off"). This computation of earnings to fixed charges is presented as if Senior Housing was a separate legal entity from HRPT prior to the Spin-Off, although no such entity existed until October 12, 1999. Interest expense was allocated based on HRPT's historical interest expense as a percentage of HRPT's average historical costs of real estate investments. The ratios of earnings to fixed charges presented above were computed by dividing Senior Housing's earnings by fixed charges. For this purpose, earnings have been calculated by adding fixed charges to income before income taxes, extraordinary items and gain or loss on the disposition of real property. Fixed charges consist of interest costs, whether expensed or capitalized, and any interest component of capitalized lease expense, amortization of debt discounts and deferred financing costs, whether expensed or capitalized. As of May 7, 2001, Senior Housing has not issued any preferred shares, and so the ratio of earnings to combined fixed charges and preferred shares distributions are the same as the ratios of earnings to fixed charges presented above.