Exhibit 12.1

ALLIANT ENERGY CORPORATION

RATIO OF EARNINGS TO FIXED CHARGES

 
Years Ended December 31,
 
2012
2011
2010
2009
2008
 
(dollars in millions)
EARNINGS:
 
 
 
 
 
Net income from continuing operations attributable to Alliant Energy Corporation common shareowners

$324.9


$323.1


$291.5


$111.6


$265.8

Income tax expense (benefit) (a)
89.4

69.2

147.7

(6.8
)
130.6

Subtotal
414.3

392.3

439.2

104.8

396.4

Fixed charges as defined
208.0

208.4

215.4

199.7

185.2

Adjustment for undistributed equity earnings
(7.1
)
(7.0
)
(5.9
)
(6.7
)
(6.1
)
Less:
 
 
 
 
 
Interest capitalized
6.1

2.7

—

—

—

Preferred dividend requirements of subsidiaries (pre-tax basis) (b)
20.1

22.0

27.6

17.7

27.3

Total earnings as defined

$589.0


$569.0


$621.1


$280.1


$548.2

 
 
 
 
 
 
FIXED CHARGES:
 
 
 
 
 
Interest expense

$156.7


$158.3


$162.8


$154.8


$125.8

Interest capitalized
6.1

2.7

—

—

—

Estimated interest component of rent expense
25.1

25.4

25.0

27.2

32.1

Preferred dividend requirements of subsidiaries (pre-tax basis) (b)
20.1

22.0

27.6

17.7

27.3

Total fixed charges as defined

$208.0


$208.4


$215.4


$199.7


$185.2

 
 
 
 
 
 
Ratio of Earnings to Fixed Charges (c)
2.83

2.73
2.88
1.40
2.96

(a) Includes net interest related to unrecognized tax benefits.

(b) Preferred dividend requirements of subsidiaries (pre-tax basis) are computed by dividing the preferred dividend requirements of subsidiaries by one hundred percent minus the respective annual effective income tax rate.

(c) The ratio calculation in the above table relates to Alliant Energy Corporation’s continuing operations.