My natural gas/propane/heating oil use varies over the course of a year. How can I get an accurate number to use in the calculator?

The most accurate way is to add up your monthly heating fuel use over the past 12 months and divide by 12 to get a monthly average. (Or, you can use the national average by clicking the box.) Then enter this number in the Therms/month or Gallons/month fields on the Heating page and click Calculate.  more