
<PAGE>

                                                                    EXHIBIT 11.1

                       CROWN CASTLE INTERNATIONAL CORP.

                            COMPUTATION OF NET LOSS
                               PER COMMON SHARE
              (IN THOUSANDS OF DOLLARS, EXCEPT PER SHARE AMOUNTS)
<TABLE>
<CAPTION>
                                                          THREE MONTHS              SIX MONTHS
                                                         ENDED JUNE 30,           ENDED JUNE 30,
                                                      --------------------     ---------------------
                                                        1999        2000         1999        2000
                                                      --------    --------     --------    ---------
<S>                                                   <C>         <C>          <C>         <C>
Loss before extraordinary item and cumulative
 effect of change in accounting principle.....        $(20,850)   $(59,230)    $(34,323)   $ (91,290)
Dividends on preferred stock..................          (6,614)    (11,725)     (13,022)     (23,218)
                                                      --------    --------     --------    ---------
Loss before extraordinary item and cumulative
 effect of change in accounting principle
 applicable to common stock for basic and
 diluted computations.........................         (27,464)    (70,955)    $(47,345)    (114,508)

Extraordinary item............................              --          --           --       (1,495)

Cumulative effect of change in accounting
 principle....................................              --          --       (2,414)          --
                                                      --------    --------     --------    ---------
Net loss applicable to common stock for basic
 and diluted computations.....................        $(27,464)   $(70,955)    $(49,759)   $(116,003)
                                                      ========    ========     ========    =========
Weighted-average number of common shares
 outstanding during the period for basic and
 diluted computations (in thousands)..........         124,849     165,625      109,791      162,095
                                                      ========    ========     ========    =========
Per common share--basic and diluted:
  Loss before extraordinary item and cumulative
   effect of change in accounting principle...        $  (0.22)   $  (0.43)    $  (0.43)   $   (0.71)

Extraordinary item............................              --          --           --        (0.01)

Cumulative effect of change in accounting
 principle....................................              --          --        (0.02)          --
                                                      --------    --------     --------    ---------
   Net loss...................................        $  (0.22)   $  (0.43)    $  (0.45)   $   (0.72)
                                                      ========    ========     ========    =========
</TABLE>
