Exhibit 12 GREAT PLAINS ENERGY COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES Year to date September 30 2002 2001 2000 1999 1998 1997 (Thousands) Income (loss) before extraordinary item and cumulative effect of changes in accounting principles $ 101,908 $ (40,043) $ 128,631 $ 81,915 $ 120,722 $ 76,560 Add: Equity investment losses 880 376 19,441 24,951 11,683 2,748 Minority interests in subsidiaries - (5,038) - 1 (2,222) (575) Income subtotal 102,788 (44,705) 148,072 106,867 130,183 78,733 Add: Taxes on income 38,571 (35,914) 53,166 3,180 32,800 8,079 Kansas City earnings tax 441 583 421 602 864 392 Total taxes on income 39,012 (35,331) 53,587 3,782 33,664 8,471 Interest on value of leased property 5,229 10,679 11,806 8,577 8,482 8,309 Interest on long-term debt 50,504 84,995 60,956 51,327 57,012 60,298 Interest on short-term debt 5,229 9,915 11,537 4,362 295 1,382 Mandatorily redeemable Preferred Securities 9,337 12,450 12,450 12,450 12,450 8,853 Other interest expense and amortization 2,794 5,188 2,927 3,573 4,457 3,990 Total fixed charges 73,093 123,227 99,676 80,289 82,696 82,832 Earnings before taxes on income and fixed charges 214,893 43,191 301,335 190,938 246,543 170,036 Ratio of earnings to fixed charges 2.94 (a) 3.02 2.38 2.98 2.05 (a) An $80.0 million deficiency in earnings caused the ratio of earnings to fixed charges to be less than one-to-one coverage. A $195.8 million net write-off before income taxes related to the bankruptcy filing of DTI was recorded in 2001.