text: (1) 
  
   Reserve replacement is calculated by dividing net reserve additions from all sources by actual production for the corresponding period. We calculate drilling and net acquisition cost per mcfe by dividing total drilling 
  and net proved property acquisition costs incurred during the year (excludes certain costs primarily related to net unproved property acquisitions, geological and geophysical costs and deferred taxes related to 
  corporate acquisitions) by total proved reserve additions excluding price-related revisions. 
   A non-GAAP financial measure, as defined below. Please refer to the Investors section of our website at www.chk.com for reconciliations of non-GAAP financial measures to comparable financial measures calculated 
  in accordance with generally accepted accounting principles. 
  • Adjusted ebitda is net income (loss) before interest expense, income tax expense (benefit), and depreciation, depletion and amortization expense, as adjusted to remove the effects of certain items that manage- 
  
  (2) 
  
  ment believes affect the comparability of operating results. 
  
  • Operating cash flow is cash provided by operating activities before changes in assets and liabilities. 
  • Adjusted earnings per fully diluted share is net income (loss) per share available to Chesapeake common stockholders, assuming dilution, as adjusted to remove the effects of certain items that management 
  believes affect the comparability of operating results. 
  (3) 
   FORTUNE 100 Best Companies to Work For® listed in the magazine’s February 7, 2011 issue. 