<PAGE>

                                                                      EXHIBIT 12

                              METALDYNE CORPORATION
         COMPUTATION OF RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND
                            PREFERRED STOCK DIVIDENDS
                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                3 MONTHS
                                  ENDED            FOR THE YEARS ENDED DECEMBER 31
                                MARCH 31, -------------------------------------------------
                                  2001      2000      1999      1998      1997       1996
                                --------  --------  --------  --------  --------  ---------
<S>                             <C>       <C>       <C>       <C>       <C>       <C>
EARNINGS BEFORE INCOME TAXES
  AND FIXED CHARGES:
  Income from continuing
    operations before income
    taxes and cumulative
    effect of accounting
    change, net................ $    730  $ 92,720  $139,470  $144,520  $190,290  $  77,220

  Deduct equity in
    undistributed earnings
    of less-than-fifty
    percent owned companies....      580    (9,180)   (9,800)   (8,530)  (46,030)   (31,650)
  Add interest on
    indebtedness, net..........   34,810    91,730    83,470    83,620    36,650     30,350
  Add amortization of debt
    expense....................    1,650     5,030     2,740     3,250       900      1,490
  Estimated interest factor
    for rentals................    1,700     3,480     3,710     3,620     2,100      6,350
                                --------  --------   -------  --------  --------  ---------
  Earnings before income
    taxes and fixed charges.... $ 39,470  $183,780  $219,590  $226,480  $183,910  $  83,760
                                ========  ========  ========  ========  ========  =========

FIXED CHARGES:

  Interest on indebtedness,
    net........................ $ 34,950  $ 91,990  $ 83,760  $ 84,080  $ 36,770  $  30,590
  Amortization of debt
    expense....................    1,650     5,030     2,740     3,250       900      1,490
  Estimated interest factor
    for rentals................    1,700     3,480     3,710     3,620     2,100      6,350
                                --------  --------  --------  --------  --------  ---------

      Total fixed charges......   38,300   100,500    90,210    90,950    39,770     38,430
                                --------  --------  --------  --------  --------  ---------
  Preferred stock dividend
    requirement (a)............    2,950       650     ---       ---      10,300     21,570
                                --------  --------  --------  --------  --------  ---------

  Combined fixed charges and
    preferred stock dividends.. $ 41,250  $101,150  $ 90,210  $ 90,950  $ 50,070  $  60,000
                                ========  ========  ========  ========  ========  =========

RATIO OF EARNINGS TO
  FIXED CHARGES................   1.0       1.8       2.4       2.5        4.6       2.2
                                  ===       ===       ===       ===        ===       ===

RATIO OF EARNINGS TO COMBINED
  FIXED CHARGES AND PREFERRED
  STOCK DIVIDENDS..............   --- (b)   1.8       2.4       2.5        3.7       1.4
                                  ===       ===       ===       ===        ===       ===
</TABLE>


(a)  Represents amount of income before provision for income taxes required to
     meet the preferred stock dividend requirements of the Company and its 50%
     owned companies.

(b)  First quarter 2001 results of operations are inadequate to cover combined
     fixed charges and preferred stock dividends by $1,780.