EXHIBIT 12 SOUTHWEST GAS CORPORATION COMPUTATION OF RATIOS OF EARNINGS TO FIXED CHARGES (Thousands of dollars) FOR THE TWELVE MONTHS ENDED ---------------------------------------------------------------------------- MARCH 31, DECEMBER 31, ----------- --------------------------------------------------------------- CONTINUING OPERATIONS 1997 1996 1995 1994 1993 1992 ----------- ----------- ----------- ----------- ----------- ----------- 1. Fixed charges: A) Interest expense $ 56,609 $ 54,674 $ 52,844 $ 48,688 $ 40,883 $ 35,533 B) Amortization 1,444 1,494 1,569 1,426 1,330 1,183 C) Interest portion of rentals 7,223 6,629 4,435 4,743 4,556 4,468 D) Preferred securities distributions 5,475 5,475 913 -- -- -- ----------- ----------- ----------- ----------- ----------- ----------- Total fixed charges $ 70,751 $ 68,272 $ 59,761 $ 54,857 $ 46,769 $ 41,184 =========== =========== =========== =========== =========== =========== 2. Earnings (as defined): E) Pretax income from continuing operations $ 21,295 $ 10,448 $ 3,493 $ 38,119 $ 21,959 $ 49,752 Fixed Charges (1. above) 70,751 68,272 59,761 54,857 46,769 41,184 ----------- ----------- ----------- ----------- ----------- ----------- Total earnings as defined $ 92,046 $ 78,720 $ 63,254 $ 92,976 $ 68,728 $ 90,936 =========== =========== =========== =========== =========== =========== 3. Ratio of earnings to fixed charges 1.30 1.15 1.06 1.69 1.47 2.21 =========== =========== =========== =========== =========== =========== FOR THE TWELVE MONTHS ENDED ---------------------------------------------------------------------------- ADJUSTED FOR INTEREST ALLOCATED TO MARCH 31, DECEMBER 31, DISCONTINUED OPERATIONS ----------- --------------------------------------------------------------- 1997 1996 1995 1994 1993 1992 ----------- ----------- ----------- ----------- ----------- ----------- 1. Fixed charges A) Interest expense $ 56,609 $ 54,674 $ 52,844 $ 48,688 $ 40,883 $ 35,533 B) Amortization 1,444 1,494 1,569 1,426 1,330 1,183 C) Interest portion of rentals 7,223 6,629 4,435 4,743 4,556 4,468 D) Preferred securities distributions 5,475 5,475 913 -- -- -- E) Allocated interest [1] -- -- 9,636 7,874 7,874 7,333 ----------- ----------- ----------- ----------- ----------- ----------- Total fixed charges $ 70,751 $ 68,272 $ 69,397 $ 62,731 $ 54,643 $ 48,517 =========== =========== =========== =========== =========== =========== 2. Earnings (as defined): F) Pretax income from continuing operations $ 21,295 $ 10,448 $ 3,493 $ 38,119 $ 21,959 $ 49,752 Fixed Charges (1. above) 70,751 68,272 69,397 62,731 54,643 48,517 ----------- ----------- ----------- ----------- ----------- ----------- Total earnings as defined $ 92,046 $ 78,720 $ 72,890 $ 100,850 $ 76,602 $ 98,269 =========== =========== =========== =========== =========== =========== 3. Ratio of earnings to fixed charges 1.30 1.15 1.05 1.61 1.40 2.03 =========== =========== =========== =========== =========== =========== [1] Represents allocated interest through the period ended December 31, 1995. Carrying costs for the period subsequent to year end through the disposition of the discontinued operations were accrued and recorded as disposal costs. EXHIBIT 12 SOUTHWEST GAS CORPORATION COMPUTATION OF RATIOS OF EARNINGS TO FIXED CHARGES AND PREFERRED DIVIDENDS (Thousands of dollars) FOR THE TWELVE MONTHS ENDED ---------------------------------------------------------------------------- MARCH 31, DECEMBER 31, ----------- --------------------------------------------------------------- CONTINUING OPERATIONS 1997 1996 1995 1994 1993 1992 ----------- ----------- ----------- ----------- ----------- ----------- 1. Combined fixed charges: A) Total fixed charges $ 70,751 $ 68,272 $ 59,761 $ 54,857 $ 46,769 $ 41,184 B) Preferred dividends [1] -- -- 404 826 1,183 1,623 ----------- ----------- ----------- ----------- ----------- ----------- Total fixed charges and preferred dividends $ 70,751 $ 68,272 $ 60,165 $ 55,683 $ 47,952 $ 42,807 =========== =========== =========== =========== =========== =========== 2. Earnings $ 92,046 $ 78,720 $ 63,254 $ 92,976 $ 68,728 $ 90,936 =========== =========== =========== =========== =========== =========== 3. Ratio of earnings to fixed charges and preferred dividends 1.30 1.15 1.05 1.67 1.43 2.12 =========== =========== =========== =========== =========== =========== FOR THE TWELVE MONTHS ENDED ---------------------------------------------------------------------------- ADJUSTED FOR INTEREST ALLOCATED TO MARCH 31, DECEMBER 31, DISCONTINUED OPERATIONS ----------- --------------------------------------------------------------- 1997 1996 1995 1994 1993 1992 ----------- ----------- ----------- ----------- ----------- ----------- 1. Combined fixed charges A) Total fixed charges $ 70,751 $ 68,272 $ 69,397 $ 62,731 $ 54,643 $ 48,517 B) Preferred dividends [1] -- -- 404 826 1,183 1,623 ----------- ----------- ----------- ----------- ----------- ----------- Total fixed charges and preferred dividends $ 70,751 $ 68,272 $ 69,801 $ 63,557 $ 55,826 $ 50,140 =========== =========== =========== =========== =========== =========== 2. Earnings $ 92,046 $ 78,720 $ 72,890 $ 100,850 $ 76,602 $ 98,269 =========== =========== =========== =========== =========== =========== 3. Ratio of earnings to fixed charges and preferred dividends 1.30 1.15 1.04 1.59 1.37 1.96 =========== =========== =========== =========== =========== =========== [1] Preferred and preference dividends have been adjusted to represent the pretax earnings necessary to cover such dividend requirements.