Building Energy Tools and Calculators

The following collection of calculators and online tools will help you analyze energy use and performance for building systems.

HVAC Systems

Building Efficiency System Tool (BEST): Calculate HVAC system installation and replacement costs, maintenance and energy costs, total system life cycle cost, system payback time and more.

Rooftop Unit Comparison Calculator: Compare high-efficiency packaged rooftop air conditioners to standard equipment in terms of lifecycle cost.

Energy Cost Savings Calculator for Air-Cooled Electric Chillers: Estimate chiller lifetime energy cost savings at various efficiency levels.

Energy Cost Savings Calculator for Commercial Boilers: Estimate the lifetime energy cost savings of closed loop boilers used for space heating at different efficiency levels.

Cool Roof Calculator: Estimate HVAC energy savings from installing a cool roof.


Street and Parking Facility Lighting Retrofit Financial Analysis Tool: Analyze the cost and return-on-investment from street and parking facility lighting efficiency projects.

Facility Systems and Equipment

MEASUR: A suite of free online tools from the U.S. Department of Energy that can help you identify and evaluate energy-saving opportunities in pumping and fan systems, process heating equipment, as well as compressed air and steam systems.

EnergySave Calculator: Compare AC drive control against numerous traditional mechanical flow control methods in three different applications: pumps, fans and compressors.

Electric Motor Calculator: Determine motor amps, horsepower and three-phase kVA at different efficiencies, power factor ratings and voltages.

3E Plus: Calculate the appropriate level of pipe insulation thickness for a variety of applications. You can also estimate insulation needed for personnel protection and condensate control, as well as calculate heat loss or gain efficiency.

Lighting and HVAC Integrated Controls Savings Estimator: Describe the characteristics of your building to get an estimate of the savings achieved through integrated controls.

Measuring and Comparing Energy Use

 Benchmark the energy performance of a building or a portfolio of buildings, and measure and track energy and water use.

Building Performance Database: Measured energy use data for thousands of commercial buildings in the U.S. Compare your energy performance against similar buildings, identify energy efficiency opportunities and track progress.

Energy Performance Indicator Tool: Establish baseline facility energy consumption and use this information to track the progress of energy efficiency upgrades, as well as calculate cost savings and avoided emissions.

Commercial Building Energy Consumption Survey: U.S. Department of Energy survey provides data on average overall building energy consumption, by end use, region and more.