<PAGE>

                                                                    Exhibit 12.1

                     CREDIT SUISSE FIRST BOSTON (USA), INC.
         STATEMENT RE COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
                             AND PREFERRED DIVIDENDS
                        (In thousands, except for ratio)

<TABLE>
<CAPTION>
                                                                      For the Years Ended
                                               -------------------------------------------------------------------
                                                  1996          1997          1998          1999          2000
<S>                                            <C>           <C>           <C>           <C>           <C>
Earnings:
          Income (loss) before provision for
              income taxes                     $   473,800   $   661,100   $   600,500   $   953,500   $(1,522,164)

Add: Fixed Charges
          Interest expense (gross)               2,865,800     4,012,209     4,501,242     4,839,810     8,161,465

               Interest factor in rents             25,515        29,351        38,517        52,563        76,191
                                               -----------   -----------   -----------   -----------   -----------

               Total fixed charges               2,891,315     4,041,560     4,539,759     4,892,373     8,237,656


Earnings before fixed charges,
   and provision for income taxes              $ 3,365,115   $ 4,702,660   $ 5,140,259   $ 5,845,873   $ 6,715,492
                                               ===========   ===========   ===========   ===========   ===========

Ratio of earnings to fixed charges                    1.16          1.16          1.13          1.19          0.82(1)
                                               ===========   ===========   ===========   ===========   ===========
</TABLE>

(1)   The dollar amount of the deficiency in the ratio of earnings to fixed
      charges was $1,522,164 for the year ended December 31, 2000.
<PAGE>

                     CREDIT SUISSE FIRST BOSTON (USA), INC.
        STATEMENT RE COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
                            AND PREFERRED DIVIDENDS
                        (In thousands, except for ratio)

<TABLE>
<CAPTION>
                                                                        For the Years Ended
                                                 -------------------------------------------------------------------
                                                     1996          1997          1998          1999          2000
<S>                                              <C>           <C>           <C>           <C>           <C>
Earnings:
          Income (loss) before provision for
              income taxes                       $   473,800   $   661,100   $   600,500   $   953,500   $(1,522,164)

Add: Fixed Charges
              Interest(gross)                      2,865,800     4,012,209     4,501,242     4,839,810     8,161,465

               Interest factor in rents               25,515        29,351        38,517        52,563        76,191
                                                 -----------   -----------   -----------   -----------   -----------

               Total fixed charges                 2,891,315     4,041,560     4,539,759     4,892,373     8,237,656

Add: Preferred dividends                              18,653        12,144        21,310        21,180        21,155

          Combined fixed charges and preferred
             dividends                             2,909,968     4,053,704     4,561,069     4,913,553     8,258,811

Earnings before fixed charges
 and provision for income taxes                  $ 3,365,115   $ 4,702,660   $ 5,140,259   $ 5,845,873   $ 6,715,492
                                                 ===========   ===========   ===========   ===========   ===========

Ratio of earnings to fixed charges
    and preferred dividends                             1.16          1.16          1.13          1.19          0.81(1)
                                                 ===========   ===========   ===========   ===========   ===========
</TABLE>

(1)   The dollar amount of the deficiency in the ratio of earnings to fixed
      charges and preferred dividends was $1,543,319 for the year ended December
      31, 2000.