EUI Calculator – Energy Use Intensity

Adjust the calculator values below

Annualized EUI 100 kWh/m²/year
US customary EUI 31.6998 kBtu/ft²/year
Energy basis Site energy
Reported energy 500,000 kWh
Annualized energy 500,000 kWh/year
Gross floor area 5,000 m²
Reporting period 12 months
Annualization factor 1×
100 kWh/m²/year
Annual site EUI 500,000 kWh over 12 months divided by 5,000 m²
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EUI Calculator – Energy Use Intensity

Use this eui calculator – energy use intensity with energy basis, total energy use, and gross floor area to get fast results, understand the formula...

How Energy Use Intensity is calculated

Energy Use Intensity expresses a building's energy use relative to its gross floor area. Annual EUI equals total energy for one year divided by gross floor area. When the entered reporting period is not one year, this calculator first annualizes the energy using 12 months or 365 days, then reports both kWh per square meter per year and kBtu per square foot per year.

Choose site energy or source energy consistently

Site energy is the energy consumed at the property, including purchased energy and renewable energy generated and consumed on site. Source energy also includes upstream generation, transmission, and distribution losses. The arithmetic is the same, but the selected basis must match the energy total and any benchmark used for comparison.

Compare EUI only with an appropriate benchmark

EUI helps compare buildings of different sizes, but building type, occupancy, operating hours, climate, weather, data centers, parking, process loads, and meter coverage can materially change the result. A lower EUI often indicates lower energy use for a similar building, but it is not a complete efficiency score and this calculator does not weather-normalize the data.

Frequently asked questions

Common questions about site and source EUI, annual energy, gross floor area, unit conversion, annualization, and building benchmarks.

What is Energy Use Intensity (EUI)?

EUI is a building's annual energy use divided by its gross floor area. It normalizes energy for building size so similarly used properties can be compared more fairly.

What is the difference between site and source EUI?

Site EUI uses energy consumed at the property. Source EUI includes the raw energy and upstream generation, transmission, and distribution losses needed to deliver it. Use the same basis for both the entered total and the benchmark.

How does the calculator annualize a partial reporting period?

A month-based total is multiplied by 12 divided by the entered months. A day-based total is multiplied by 365 divided by the entered days. This assumes the measured period is representative of a full year.

Can I enter utility energy in different units?

Yes. Enter kWh, MWh, GJ, kBtu, or MMBtu. The calculator converts the total internally and displays EUI in both kWh/m²/year and kBtu/ft²/year.

Does lower EUI always mean a more efficient building?

Not by itself. Compare the same property type, energy basis, meter coverage, climate treatment, occupancy, and operating schedule. Hospitals, data centers, schools, warehouses, and offices have very different normal loads.

Is this EUI weather-normalized?

No. It annualizes the entered period but does not adjust for unusually hot or cold weather. Use a benchmarking platform with weather normalization when that distinction matters.