EXHIBIT 12 NORTHWEST NATURAL GAS COMPANY Computation of Ratio of Earnings to Fixed Charges January 1, 1995 - March 31, 2000 Twelve Months Year Ended Dec. 31, Ended --------------------------------------------------------------------- March 31, 1995 1996 1997 1998 1999 2000 ----------- ------------ ----------- ----------- ------------ --------- Fixed Charges, as Defined: Interest on Long-Term Debt $ 23,141 $ 23,176 $ 24,904 $ 27,389 $ 27,728 $ 28,163 Other Interest 2,252 3,448 4,500 4,909 2,778 2,766 Amortization of Debt Discount and Expense 882 865 730 714 699 696 Interest Portion of Rentals 1,764 1,798 2,111 1,986 1,707 1,707 ----------- ------------ ----------- ----------- ------------ ------------ Total Fixed Charges, as defined $ 28,039 $ 29,287 $ 32,245 $ 34,998 $ 32,912 $ 33,332 =========== ============ =========== =========== ============ ============ Earnings, as defined: Net Income $ 38,065 $ 46,793 $ 43,059 $ 27,301 $ 45,296 $ 52,915 Taxes on Income 22,120 27,347 21,034 14,604 24,591 27,640 Fixed Charges, as above 28,039 29,287 32,245 34,998 32,912 33,332 ----------- ------------ ----------- ----------- ------------ ------------ Total Earnings, as defined $ 88,224 $ 103,427 $ 96,338 $ 76,903 $ 102,799 $ 113,887 =========== ============ =========== =========== ============ ============ Ratio of Earnings to Fixed Charges 3.15 3.53 2.99 2.20 3.12 3.42 =========== ============ =========== =========== ============ ============