Building Energy Use Intensity (EUI) Calculator

Translate annual utility data and building size into site energy use intensity so you can compare performance against ENERGY STAR® targets, codes, and corporate decarbonisation plans.

Sum the building's purchased and generated electricity over the last 12 months.
Enter total therms burned on-site; leave blank if not applicable.
District steam, fuel oil, propane, or biomass expressed in MMBtu for the same period.
Conditioned floor area used in benchmarking studies.

Educational estimate. Consult a certified energy auditor for regulatory reporting or investment-grade analyses.

Examples

  • 1,200,000 kWh electricity, 80,000 therms gas, 5 MMBtu other fuels, 250,000 ft² ⇒ Site EUI: 48.40 kBtu/ft²·yr | Equivalent: 152.68 kWh/m²·yr
  • 650,000 kWh electricity, 0 therms gas, 12 MMBtu biomass, 98,000 ft² ⇒ Site EUI: 22.75 kBtu/ft²·yr | Equivalent: 71.78 kWh/m²·yr

FAQ

Can I use monthly bills instead of annual totals?

Yes. Sum the most recent 12 months of utility data so seasonal loads are fully represented and the EUI reflects a complete year.

How do I adjust for partial building occupancy?

If a portion of the floor area is vacant, calculate EUI twice—once with gross area for compliance reporting, and once with occupied area to understand active intensity.

What is the difference between site and source EUI?

Site EUI uses the energy that crosses your meter, while source EUI adds upstream generation and transmission losses. Multiply electricity use by the appropriate source factor to approximate source EUI.

Additional Information

  • Site EUI divides on-site energy by gross floor area, aligning with ENERGY STAR® Portfolio Manager conventions.
  • Electricity is converted to kBtu by multiplying kilowatt-hours by 3.412; therms are multiplied by 100, and MMBtu inputs are scaled by 1,000.
  • To approximate source EUI, multiply electricity consumption by your regional source factor (typically 2.8–3.2 in North America) before rerunning the calculation.
  • Benchmark intensities by building type—offices, labs, hospitals, and data centres carry very different expected ranges.

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