On average, homes in the Midwest use between 60 and 80 million British Thermal Units (BTU) each winter. Each form of heating, whether electric, fuel oil, natural gas or propane, produces a set amount of BTUs per standard measuring unit. Determining your home's heating oil usage allows you to develop an estimate of total heating cost per winter. Such estimates allow you to compare other heating options and may even be useful in establishing a ballpark budget for your heating costs.
Approximate your heating needs in BTU per winter. Using your home's square footage, insulation and climate, you can arrive at a ballpark figure for heating needs. There are many calculators online that can help you determine the BTU range required to heat your space.
Determine total BTU requirement. No furnace operates at 100 per cent efficiency. Each gallon of fuel oil has 140,000 BTUs, but a furnace that operates at 50 per cent efficiency requires 280,000 BTUs worth of fuel oil to produce 140,000 BTUs of usable heat. With that furnace, a room that requires 140,000 BTUs to heat needs two gallons to keep comfortable. To determine total need, divide total BTUs required by per cent efficiency (expressed as a decimal, such as 50 per cent equals .50). Per cent efficiency can be located on the heating system.
Divide your total BTU requirement, adjusted for your heating system's efficiency, by 140,000. The result provides you with the total number of gallons needed to heat your home based on the approximate heating need. For a better idea of average usage, repeat the same equation for high and low BTU-need estimates. Weather can vary greatly year to year and drastically impact your total heating usage.