<PAGE>   1
                                                                      EXHIBIT 12

               Computation of Ratio of Earnings to Fixed Charges
                         J.P. Morgan & Co. Incorporated
                                  Consolidated

<TABLE>
<CAPTION>
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Dollars in millions
                                           Twelve months ended December 31
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                                        1997     1996    1995    1994    1993
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<S>                                  <C>      <C>      <C>     <C>     <C>
Earnings:
  Net income                         $ 1 465  $ 1 574   1 296  $1 215  $1 723
  Add: income taxes                      689      758     610     610     968
  Less: equity in undistributed
    income of all affiliates
    accounted for by the
    equity method                         40       25      16      21      50
  Add: fixed charges, excluding
    interest on deposits               7 756    6 502   5 452   4 483   3 781
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  Earnings available for fixed
    charges, excluding interest
    on deposits                        9 870    8 809   7 342   6 287   6 422
  Add: interest on deposits            2 753    2 541   2 520   1 946   1 917
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  Earnings available for fixed
    charges, including interest
    on deposits                       12 623   11 350   9 862   8 233   8 339
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Fixed charges:
  Interest expense, excluding
    interest on deposits               7 728    6 470   5 414   4 452   3 753
  Interest factor in net
    rental expense                        28       32      38      31      28
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  Total fixed charges, excluding
    interest on deposits               7 756    6 502   5 452   4 483   3 781
  Add: interest on deposits            2 753    2 541   2 520   1 946   1 917
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Total fixed charges, including
  interest on deposits                10 509    9 043   7 972   6 429   5 698
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Ratio of earnings to fixed charges:
  Excluding interest on deposits        1.27     1.35    1.35    1.40    1.70(a)
  Including interest on deposits        1.20     1.26    1.24    1.28    1.46(a)
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<FN>
(a) For the year ended December 31, 1993, the ratio of earnings to fixed
charges, including the cumulative effect of a change in the method of
accounting for postretirement benefits other than pensions, was 1.64 excluding
interest on deposits and 1.43 including interest on deposits.
</TABLE>
<PAGE>   2
<TABLE>
<CAPTION>
                                                                                 EXHIBIT 12

           Computation of Ratio of Earnings to Combined Fixed Charges and Preferred Stock Dividends
                                         J.P. Morgan & Co. Incorporated
                                                 Consolidated
---------------------------------------------------------------------------------------------------------------
Dollars in millions

                                                                  Twelve months ended December 31
---------------------------------------------------------------------------------------------------------------
                                                         1997        1996       1995        1994        1993
---------------------------------------------------------------------------------------------------------------
<S>                                                   <C>         <C>          <C>        <C>         <C>
Earnings:
  Net income                                          $ 1 465     $ 1 574     $1 296      $1 215      $1 723
  Add: income taxes                                       689         758        610         610         968
  Less: equity in undistributed income
    of all affiliates accounted for by
    the equity method                                      40          25         16          21          50
  Add: fixed charges, excluding interest
    on deposits and preferred stock
    dividends                                           7 756       6 502      5 452       4 483       3 781
---------------------------------------------------------------------------------------------------------------
  Earnings available for fixed charges,
    excluding interest on deposits                      9 870       8 809      7 342       6 287       6 422
  Add: interest on deposits                             2 753       2 541      2 520       1 946       1 917
---------------------------------------------------------------------------------------------------------------
  Earnings available for fixed charges,
    including interest on deposits                     12 623      11 350      9 862       8 233       8 339
---------------------------------------------------------------------------------------------------------------
Fixed charges:
  Interest expense, excluding interest on
    deposits                                            7 728       6 470      5 414       4 452       3 753
  Interest factor in net rental expense                    28          32         38          31          28
  Preferred stock dividends                                51          49         35          30          28
---------------------------------------------------------------------------------------------------------------
Total fixed charges, excluding interest
  on deposits                                           7 807       6 551      5 487       4 513       3 809
  Add: interest on deposits                             2 753       2 541      2 520       1 946       1 917
---------------------------------------------------------------------------------------------------------------
Total fixed charges, including interest
  on deposits                                          10 560       9 092      8 007       6 459       5 726
---------------------------------------------------------------------------------------------------------------
Ratio of earnings to fixed charges:
  Excluding interest on deposits                         1.26        1.34       1.34        1.39        1.69(a)
  Including interest on deposits                         1.20        1.25       1.23        1.27        1.46(a)
---------------------------------------------------------------------------------------------------------------

<FN>
(a) For the year ended December 31, 1993, the ratio of earnings to combined fixed charges and preferred stock
    dividends, including the cumulative effect of a change in the method of accounting for postretirement
    benefits other than pensions, was 1.63 excluding interest on deposits and 1.42 including interest on
    deposits.
</TABLE>