<PAGE>
 
                                                                      EXHIBIT 11
 
 
                VARCO INTERNATIONAL, INC.
                Statement Re Computation of Per Share Earnings
<TABLE> 
<CAPTION> 
                                                             Three Months
                                                             Ended March 31 1996
                                                             -------------------
<S>                                                          <C> 
A.  CALCULATION OF ADJUSTED EARNINGS
 
    Net Income After Tax                                         $ 3,028,000
 
</TABLE> 
 
<TABLE> 
<CAPTION> 
                                                                                         Average        Stock       
                                                                      Total Number        Number       Option     Shares Used   
                                                       Number of   of Shares after     of Shares   Equivalent    To Calculate
                                                            Days          Weighing   Outstanding       Shares             EPS
                                                       ---------   ---------------   -----------   ----------    ------------
<S>                                                    <C>         <C>               <C>           <C>           <C> 
B.  CALCULATION OF AVERAGE SHARES OUTSTANDING
 
    Common Stock Outstanding from time-to-time during:
 
    Three Months Ended March 31, 1996                      91       2,747,512,520     30,192,445     535,138      30,727,583
</TABLE> 

C.  CALCULATION OF EARNINGS PER SHARE
 
    Income Per Share =     Net Income After Tax
                           ------------------------
                           Total Shares Outstanding

    Income Per Share =
<TABLE> 
      <S>                                        <C>                             <C> 
      Three Months Ended March 31, 1996                3,028,000        =        $0.10
                                                 ---------------
                                                      30,727,583
</TABLE> 
 
                VARCO INTERNATIONAL, INC.
                Statement Re Computation of Per Share Earnings
<TABLE> 
<CAPTION> 
                                                             Three Months
                                                             Ended March 31 1997
                                                             -------------------
<S>                                                          <C> 
A.  CALCULATION OF ADJUSTED EARNINGS
 
    Net Income After Tax                                         $ 7,384,000
</TABLE> 
 
<TABLE> 
<CAPTION> 
                                                                                         Average        Stock       
                                                                      Total Number        Number       Option     Shares Used   
                                                       Number of   of Shares after     of Shares   Equivalent    To Calculate
                                                            Days          Weighing   Outstanding       Shares             EPS
                                                       ---------   ---------------   -----------   ----------    ------------
<S>                                                    <C>         <C>               <C>           <C>           <C> 
B.  CALCULATION OF AVERAGE SHARES OUTSTANDING
 
    Common Stock Outstanding from time-to-time during:
 
      Three Months Ended March 31, 1997                    90       2,846,385,246    31,626,503      758,079      32,384,582
</TABLE> 
                                
C.  CALCULATION OF EARNINGS PER SHARE
 
    Income Per Share =     Net Income After Tax
                           ------------------------
                           Total Shares Outstanding

    Income Per Share =

<TABLE> 
      <S>                                        <C>                             <C> 
      Three Months Ended March 31, 1997                7,384,000        =        $0.23
                                                 ---------------
                                                      32,384,582
</TABLE>