<PAGE>   1
                                                                    EXHIBIT 12.1

                      UNIVERSAL COMPRESSION HOLDINGS, INC.
               COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                                     FOR THE PERIOD                       PRO FORMA
                                                  FROM DECEMBER 12, 1997 (INCEPTION)      YEAR ENDED           YEAR ENDED
                                                 THROUGH MARCH 31, 1998                 MARCH 31, 1998       MARCH 31, 1999
                                                 ----------------------------------     --------------       --------------
<S>                                              <C>                                   <C>              <C>
Fixed Charges as Defined:
  Interest expense, including amortization of
     deferred financing charges...............               $3,203                        $32,474              $29,313
  Interest component of rental expense on
     operating leases.........................                   14                            144                  142
                                                             ------                        -------               ------
       Total Fixed Charges....................               $3,217                        $32,618               29,455
                                                             ------                        -------               ------
                                                             ------                        -------               ------
Earnings as Defined:
  Net Income..................................               $  430                        $(3,214)              (2,361)
  Income Tax..................................                  409                         (1,888)              (1,031)
  Total Fixed Charges.........................                3,217                         32,618               29,455
                                                             ------                        -------               ------
       Total Earnings as Defined..............                4,056                         27,516               26,063
                                                             ------                        -------               ------
                                                             ------                        -------               ------
Ratio of Earnings to Fixed Charges............                  1.3                            0.8                  0.9
</TABLE>
<PAGE>   2
                                                                    EXHIBIT 12.1

                          UNIVERSAL COMPRESSION, INC.
               COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                                                FOR THE PERIOD                      PRO FORMA
                                                             FROM DECEMBER 12, 1997 (INCEPTION)     YEAR ENDED         YEAR ENDED
                                                             THROUGH MARCH 31, 1998                MARCH 31, 1998    MARCH 31, 1999
                                                             ----------------------------------    --------------    --------------
<S>                                                          <C>                                   <C>               <C>
Fixed Charges as Defined:
  Interest expense, including amortization of deferred
     financing charges....................................                 $2,896                       $29,082           $26,251
  Interest component of rental expense on operating
     leases...............................................                     14                           144               142
                                                                           ------                       -------           -------
       Total Fixed Charges................................                 $2,910                       $29,226           $26,393
                                                                           ======                       =======           =======
Earnings as Defined:
  Net Income..............................................                 $  617                       $(1,077)             (489)
  Income Tax..............................................                    530                          (633)              166
  Total Fixed Charges.....................................                  2,910                        29,226            26,393
                                                                           ------                       -------           -------
       Total Earnings as Defined..........................                  4,056                        27,516            26,070
                                                                           ======                       =======           =======
Ratio of Earnings to Fixed Charges........................                    1.4                           0.9               1.0
</TABLE>
<PAGE>   3


                                                                    EXHIBIT 12.1

                      TIDEWATER COMPRESSION SERVICE, INC.
               COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                                FOR THE FISCAL YEAR ENDED
                                                         MARCH 31,                   FOR THE PERIOD
                                              -----------------------------        FROM APRIL 1, 1997
                                               1995       1996       1997       THROUGH FEBRUARY 20, 1998
                                              -------    -------    -------     -------------------------
<S>                                           <C>        <C>        <C>         <C>
Fixed Charges as Defined:
  Interest expense, including amortization
     of deferred financing charges.........   $ 3,469    $ 3,706    $    --             $    --
  Interest component of rental expense on
     operating leases......................       126        159        143                 130
                                              -------    -------    -------             -------
       Total Fixed Charges.................   $ 3,595    $ 3,865    $   143             $   130
                                              -------    -------    -------             -------
                                              -------    -------    -------             -------
Earnings as Defined:
  Net income...............................   $ 6,319    $ 5,972    $ 7,842             $10,759
  Income Tax...............................     4,648      3,745      4,724               6,271
  Total Fixed Charges......................     3,595      3,865        143                 130
                                              -------    -------    -------             -------
       Total Earnings as Defined...........   $14,562    $13,582    $12,709             $17,160
                                              -------    -------    -------             -------
                                              -------    -------    -------             -------
Ratio of Earnings to Fixed Charges.........       4.1        3.5       88.9               132.1
</TABLE>