I used 1.5 cords of wood during the 4 weeks of mid jan to mid february. I live in maine and it was colder than normal this year, it hit -25 degrees on night. I heat 3100 square feet and heat my hot water. I have a greenwood aspen 175. I have used less wood now that it is march. I have kept a detailed journal of my wood usage and i predict that i will use 6 cords of wood from November to May.
Last year i used 150 gallons of oil during the same time, as a rule of thumb i would say one cord of wood should equal 100 gallons of oil if the wood boiler is of good quality and a gasification type and the house is insulated well. my two neighbors each have the central classic and go through 8 - 10 cords for houses half the size. They can burn green wood but much more of it. But they like it that way.