🏢 EUI Calculator – Energy Use Intensity
Calculate your building’s Energy Use Intensity (EUI), a standard measure of how much energy a building uses relative to its size.
What is Energy Use Intensity?
Energy Use Intensity (EUI) is a standard metric, popularized by the ENERGY STAR Portfolio Manager and used across building science, that expresses a building’s annual energy consumption per unit of floor area. It lets you compare energy performance across buildings of different sizes.
How this calculator works
The calculator converts all your fuel sources into a common unit, thousand British Thermal Units (kBtu): electricity is converted at 3.412 kBtu per kWh, and natural gas at 100 kBtu per therm. It then sums these into total annual site energy and divides by your building’s gross floor area to produce EUI in kBtu per square foot per year.
Lower EUI generally indicates better energy efficiency, though typical benchmark values vary widely by building type and climate. This is a simplified site-energy calculation for general planning; official ENERGY STAR scoring also factors in climate, occupancy, and other adjustments.