<Page>
Exhibit 12.1
Computation of ratio of earnings to fixed charges and ratio of earnings to fixed
charges and preferred stock dividends ($ in millions)
<Table>
<Caption>
Three months Three months Twelve months
ended ended ended
March 31, March 31, December 31,
Line # CONSOLIDATED BASIS Line Ref. 2003 2002 2002
- ------ ------------------ --------- ------------ ------------ -------------
1a Pretax earnings (loss) from continuing operations $146.0 ($9.1) $119.4
1b Less undistributed earnings in unconsolidated affiliates n/a n/a n/a
2 Interest expense 13.6 18.2 71.8
3 Portion of rent representative of interest exp 2.1 2.1 8.3
------- ------- -------
4 Operating earnings as adjusted 1a+1b+2+3 161.7 11.2 199.5
======= ======= =======
5 Preferred stock dividend requirements 7.6 7.6 30.3
6 Effective percent. for dividend gross-up (1-eff .tax rate) 100%-14 0.7 1.0 0.9
------- ------- -------
7 Effective preferred stock div. requirements 5/6 11.1 7.6 33.6
8 Interest expense 2 13.6 18.2 71.8
9 Portion of rent representative of interest exp 3 2.1 2.1 8.3
------- ------- -------
10 Total fixed charges and preferred stock dividends 7+8+9 26.8 27.9 113.7
======= ======= =======
11 Ratio of earnings to fixed charges
and preferred stock dividends 4/10 6.0 X 0.4 X 1.8 X
======= ======= =======
Fixed charges exceed earnings
Effective tax rate:
12 Pretax loss 1 146.0 (9.1) 119.4
13 Income tax expense (benefit) 46.1 n/a*** 11.7
------- ------- -------
14 Effective tax rate for pref. stock gross-up 13/12 0.3 n/a*** 0.1
======= ======= =======
<Caption>
Twelve months Twelve months Twelve months
ended ended ended
December 31, December 31, December 31,
Line # CONSOLIDATED BASIS Line Ref. 2001 2000 1999
- ------ ------------------ --------- ------------- ------------- -------------
1a Pretax earnings (loss) from continuing operations ($427.5) $355.4 $161.5
1b Less undistributed earnings in unconsolidated affiliates n/a (1.0) (29.0)
2 Interest expense 45.7 16.1 14.7
3 Portion of rent representative of interest exp 7.7 0.9 0.6
-------- ------- --------
4 Operating earnings as adjusted 1a+1b+2+3 (374.1) 371.4 147.8
======== ======= ========
5 Preferred stock dividend requirements 18.1 0.0 0.0
6 Effective percent. for dividend gross-up (1-eff .tax rate) 100%-14 1.0 0.0 0.0
-------- ------- --------
7 Effective preferred stock div. requirements 5/6 18.1 0.0 0.0
8 Interest expense 2 45.7 16.1 14.7
9 Portion of rent representative of interest exp 3 7.7 0.9 0.6
-------- ------- --------
10 Total fixed charges and preferred stock dividends 7+8+9 71.5 17.0 15.3
======== ======= ========
11 Ratio of earnings to fixed charges
and preferred stock dividends 4/10 (5.2)X 21.8 X 9.6 X
======== ======= ========
Effective tax rate:
12 Pretax loss 1 (427.5) 355.4 161.5
13 Income tax expense (benefit) n/a*** n/a n/a
-------- ------- --------
14 Effective tax rate for pref. stock gross-up 13/12 n/a*** n/a n/a
======== ======= ========
<Caption>
Twelve months
ended
December 31,
Line # CONSOLIDATED BASIS Line Ref. 1998
- ------ ------------------ --------- -------------
1a Pretax earnings (loss) from continuing operations $79.6
1b Less undistributed earnings in unconsolidated affiliates (17.2)
2 Interest expense 13.7
3 Portion of rent representative of interest exp 0.6
-------
4 Operating earnings as adjusted 1a+1b+2+3 76.7
=======
5 Preferred stock dividend requirements 0.0
6 Effective percent. for dividend gross-up (1-eff .tax rate) 100%-14 0.0
-------
7 Effective preferred stock div. requirements 5/6 0.0
8 Interest expense 2 13.7
9 Portion of rent representative of interest exp 3 0.6
-------
10 Total fixed charges and preferred stock dividends 7+8+9 14.3
=======
11 Ratio of earnings to fixed charges
and preferred stock dividends 4/10 5.4 X
=======
Fixed charges exceed earnings
Effective tax rate:
12 Pretax loss 1 79.6
13 Income tax expense (benefit) n/a
-------
14 Effective tax rate for pref. stock gross-up 13/12 n/a
=======
</Table>
n/a - earnings in affiliates already excluded from earnings
n/a*** due to loss in period
WHITE MOUNTAINS/FUND AMERICAN
RATIO OF EARNINGS TO FIXED CHARGES
PERIODS ENDED DECEMBER 31, 1996 THROUGH 2002
<Table>
<Caption>
Three months Three months Twelve months
ended ended ended
March 31, March 31, December 31,
Line # CONSOLIDATED BASIS Line Ref. 2003 2002 2002
- ------ ------------------ --------- ------------ ------------ -------------
1a Pretax earnings (loss) from continuing operations $146.0 ($9.1) $119.4
1b Less undistributed earnings in unconsolidated affiliates n/a n/a n/a
2 Interest expense 13.6 18.2 71.8
3 Portion of rent representative of interest exp 2.1 2.1 8.3
------- ------- -------
4 Operating earnings as adjusted 1a+1b+2+3 161.7 11.2 199.5
======= ======= =======
8 Interest expense 2 13.6 18.2 71.8
9 Portion of rent representative of interest exp 3 2.1 2.1 8.3
------- ------- -------
10 Total fixed charges 7+8+9 15.7 20.3 80.1
======= ======= =======
11 Ratio of earnings to fixed charges 4/10 10.3 X 0.6 X 2.5 X
======= ======= =======
<Caption>
Twelve months Twelve months Twelve months
ended ended ended
December 31, December 31, December 31,
Line # CONSOLIDATED BASIS Line Ref. 2001 2000 1999
- ------ ------------------ --------- ------------- ------------- -------------
1a Pretax earnings (loss) from continuing operations ($427.5) $355.4 $161.5
1b Less undistributed earnings in unconsolidated affiliates n/a (1.0) (29.0)
2 Interest expense 45.7 16.1 14.7
3 Portion of rent representative of interest exp 7.7 0.9 0.6
-------- ------- --------
4 Operating earnings as adjusted 1a+1b+2+3 (374.1) 371.4 147.8
======== ======= ========
8 Interest expense 2 45.7 16.1 14.7
9 Portion of rent representative of interest exp 3 7.7 0.9 0.6
-------- ------- --------
10 Total fixed charges 7+8+9 53.4 17.0 15.3
======== ======= ========
11 Ratio of earnings to fixed charges 4/10 (7.0)X 21.8 X 9.6 X
======== ======= ========
<Caption>
Twelve months
ended
December 31,
Line # CONSOLIDATED BASIS Line Ref. 1998
- ------ ------------------ --------- -------------
1a Pretax earnings (loss) from continuing operations $79.6
1b Less undistributed earnings in unconsolidated affiliates (17.2)
2 Interest expense 13.7
3 Portion of rent representative of interest exp 0.6
-------
4 Operating earnings as adjusted 1a+1b+2+3 76.7
=======
8 Interest expense 2 13.7
9 Portion of rent representative of interest exp 3 0.6
-------
10 Total fixed charges 7+8+9 14.3
=======
11 Ratio of earnings to fixed charges 4/10 5.4 X
=======
</Table>
n/a - earnings in affiliates already excluded from earnings