<PAGE>

                                  Exhibit 11.0
                              Roslyn Bancorp, Inc.
              Statement Re: Computation of Per Share Earnings (1)
               (In thousands, except share and per share amounts)
                                  (Unaudited)


<TABLE>
<CAPTION>
                                                                      For the                        For the
                                                                 Three Months Ended             Three Months Ended
                                                                   June 30, 2001                  June 30, 2000
                                                            --------------------------     --------------------------
<S>                                                         <C>                            <C>
Net income                                                        $             26,985           $             25,032
                                                            --------------------------     --------------------------

Weighted average common shares outstanding                                  86,829,366                     95,452,580
                                                            --------------------------     --------------------------

Basic earnings per common share                                   $               0.31           $               0.26
                                                            ==========================     ==========================

Weighted average common shares outstanding                                  86,829,366                     95,452,580

Potential common stock due to dilutive effect of stock
 options                                                                     1,570,295                      1,067,635
                                                            --------------------------     --------------------------

Total shares for diluted earnings per share                                 88,399,661                     96,520,215
                                                            ==========================     ==========================

Diluted earnings per common share                                 $               0.31           $               0.26
                                                            ==========================     ==========================
</TABLE>

<TABLE>
<CAPTION>
                                                                      For the                        For the
                                                                  Six Months Ended               Six Months Ended
                                                                   June 30, 2001                  June 30, 2000
                                                            --------------------------     --------------------------
<S>                                                         <C>                           <C>
Net income                                                        $             52,312           $             48,526
                                                            --------------------------     --------------------------

Weighted average common shares outstanding                                  87,177,818                     97,834,790
                                                            --------------------------     --------------------------

Basic earnings per common share                                   $               0.60           $               0.50
                                                            ==========================     ==========================

Weighted average common shares outstanding                                  87,177,818                     97,834,790

Potential common stock due to dilutive effect of stock
 options                                                                     1,473,601                      1,064,088
                                                            --------------------------     --------------------------

Total shares for diluted earnings per share                                 88,651,419                     98,898,878
                                                            ==========================     ==========================

Diluted earnings per common share                                 $               0.59           $               0.49
                                                            ==========================     ==========================
</TABLE>

(1) Adjusted to reflect a 3-for-2 stock split.

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