Exhibit 12.1



MPLX LP
Computation of Ratio of Earnings to Fixed Charges
TOTAL ENTERPRISE BASIS - Unaudited
(In millions)


 
For the Three Months Ended
 
For the Years Ended December 31,
 
March 31,
2016
 
2015
 
2014
 
2013
 
2012
 
2011
Portion of rentals representing interest
$
3

 
$
7

 
 
$
6

 
 
$
6


 
 
$
5


 
 
$
2


 
Capitalized interest
7

 
5

 
 
1

 
 
1
 

 
 
1
 

 
 
1
 

 
Other interest and fixed charges
67

 
40

 
 
4

 
 
—
 

 
 
—
 

 
 
—
 

 
Total fixed charges (A)
$
77

 
$
52

 
 
$
11

 
 
$
7


 
 
$
6


 
 
$
3


 
 
 
 
 
 
 
 
 
 
 
 
 
Earnings-pretax income with applicable adjustments (B)
$
62

 
$
310

 
 
$
252

 
 
$
220


 
 
$
211


 
 
$
166


 
 
 
 
 
 
 
 
 
 
 
 
 
Ratio of (B) to (A)
0.8

 
6.0

 
 
22.9

 
 
31.4
 

 
 
35.2
 

 
 
55.3