<PAGE>
 
                                                                      Exhibit 11

                       COMPUTATION OF EARNINGS PER SHARE

        For the three and nine months ended December 31, 1996 and 1995

                                  (Unaudited)

<TABLE> 
<CAPTION> 
                                                             Three Months Ended                  Nine Months Ended
                                                                 December 31                        December 31, 
                                                            1996            1995                1996            1995  
<S>                                                       <C>            <C>                <C>              <C> 
Primary Earnings per Share 
Net income applicable to common stock                     $  417,168     $  476,278         $  244,056       $1,320,287  
Weighted average number of common shares                  ==========     ==========         ==========       ========== 
  outstanding                                                819,979        849,893            819,459          855,363  
Common shares issuable under employee stock                                                              
  option plan                                                 61,317         51,139             61,317           51,139  
Less shares assumed repurchased with proceeds                (27,453)       (28,952)           (27,453)         (28,952) 
                                                          ----------     ----------         ----------       ----------
Weighted average common shares and common                                                                
   share equivalents outstanding                             853,843        872,080            853,324          877,550  
                                                          ==========     ==========         ==========       ==========
Primary earnings  per common share                        $     0.49     $     0.55         $     0.29       $     1.50  
                                                          ==========     ==========         ==========       ==========
Fully Diluted Earnings Per Share                                                                 

Net income applicable to common stock                     $  417,168     $  476,278         $  244,056       $1,320,287  
Interest on convertible subordinated debentures,                                                                 
  net of tax                                                 172,991         45,509            518,972           45,509  
                                                          ----------     ----------         ----------       ----------
Net income  adjusted                                      $  590,159     $  521,787         $  763,028       $1,365,796
                                                          ==========     ==========         ==========       ==========
Weighted average common share and common                                                                 
  share equivalents outstanding                              853,843        872,080            853,324          877,550  
Weighted average common shares issuable with                                                             
  the conversion of debentures to common stock               560,182        152,223            560,182           50,926
                                                          ----------     ----------         ----------       ----------
Weighted average common shares and common share 
  equivalents                                              1,414,025      1,024,303          1,413,506          928,476  
                                                          ==========     ==========         ==========       ==========
Fully diluted earnings per common share                   $     0.42     $     0.51         $     0.54       $     1.47
                                                          ==========     ==========         ==========       ==========
</TABLE> 
                                                                 
    Fully diluted earnings per share are not disclosed on the statement of 
operations as they are anti-dilutive for the nine months ended December 31, 1996