Energy Cost and Carbon Calculator

At your office or on the jobsite, use the energy calculator to compare annual costs and carbon emissions of space heating and water heating systems.

What is your answer when a homeowner asks, “Which system costs less to operate?” The question is common, but it’s hard to answer because it depends on so many variables. How old is the current heating system? How leaky is the house? How much hot water will the family use? What’s the energy type?

The Heating Energy Cost and Carbon Calculator can help construction pros answer that question by estimating the annual energy costs for space heating or water heating, based on a virtual prototype home similar to the one entered by the user. By focusing on mechanical system specifications only and using virtually modeled prototype homes, the calculator can disregard all the real-world variables that affect the performance of heating systems and produce an “apples to apples” comparison of energy costs.

Download the mobile app

The Energy Cost and Carbon Calculator mobile app allows you to compare heating system results side by side, on the go. Get it free for iOS and Android operating systems.

To get started, you simply enter essential information, such as location of the home, system type, and efficiency rating, and the app figures out the estimated amount the homeowner will pay each year. For each calculation, the app provides the same estimate for a comparable Energy Star rated system, which can serve as a baseline for comparison against the user-entered system. The calculator estimates the annual energy cost and carbon emissions you can expect from a space or water heating system using propane, fuel oil, or electricity a big difference from other calculation apps that only work with one energy type.

Explore the interactive tool

The interactive Energy Calculator tool provides the same in-depth energy cost data as the mobile app. Start comparing systems now by exploring the module below.

Here’s how we compare costs

The calculator provides suggested equipment efficiency ratings based on the regional climate and the typical decline in equipment efficiency that comes with normal use. Formulas that estimate efficiency decline over time are from the Department of Energy (DOE). Default values for energy prices are from 2010 state-level pricing data collected by the DOE’s Energy Information Administration.

Because the energy cost estimates produced by the calculator are based on virtually modeled prototype homes, actual energy costs will vary due to unavoidable differences between real and prototype homes, as well as unpredictable factors such as weather and homeowner behavior.

Please note that the calculator is designed to assist users to compare propane systems against likely alternatives, such as oil or electric systems. The calculator is also meant to provide comparisons for homes in areas where propane is a common energy choice. Because propane is not typically used in areas where natural gas is available, the calculator does not offer natural gas as an energy option.

Carbon emissions comparisons

For construction pros working with green buyers, the calculator also provides estimated CO2 emissions associated with the operation of the systems.

The calculator estimates CO2 emissions based on state-level data provided by the EPA and DOE. These data identify the amount of CO2 released during the production of the energy consumed at home. For example, a state’s electricity emissions factor comes from the type, size, efficiency, and energy source such as coal, natural gas, nuclear, hydro, and wind of its electricity generation plants. Emissions factors for propane and fuel oil are generally lower than emissions factors for electricity. This is because the largest portion of electricity generated in the United States is from coal-fired power plants, which are intensive producers of carbon emissions.

Every 2,000 pounds (1 ton) of CO2 emissions avoided or eliminated is the equivalent to the CO2 emissions from 0.174 typical passenger cars driven for a year. Stated another way, the annual emissions from a passenger car are offset by every 5.76 tons of CO2 reduction.