Gas Vs Electric Heat Cost Calculator

An expert tool for homeowners and renters.

Deciding between gas and electric heating involves balancing unit costs, appliance efficiency, and usage patterns. This calculator provides a detailed operational cost comparison to help you make an informed financial decision. Enter your local utility rates and home heating needs to see which option is more budget-friendly.

Enter your values to see the cost comparison.

Cost Comparison Chart

Visual comparison of estimated monthly and annual heating costs.

What is a Gas vs Electric Heat Cost Calculator?

A gas vs electric heat cost calculator is a tool designed to estimate and compare the running costs of two of the most common home heating methods: natural gas furnaces and electric heating systems. While gas is often cheaper per energy unit, the efficiency of the appliances plays a crucial role in the final cost. This calculator helps users move beyond simple unit price comparisons by incorporating the real-world performance of their heating equipment.

This tool is for homeowners, renters, and property investors who want to understand the financial implications of their heating choices. By inputting local utility rates, estimated daily usage, and appliance efficiency, you can generate a clear, data-driven comparison. A common misunderstanding is that a lower price per unit of energy always results in a lower bill. However, a highly efficient electric heat pump can sometimes be cheaper to run than an inefficient gas furnace, even if the electricity price per kilowatt-hour (kWh) is higher than the gas price per therm.

The Formula and Explanation for Heating Costs

The calculation boils down to determining the total amount of heat energy required and then finding the cost to produce that heat with each fuel source, adjusted for appliance efficiency. The key is to convert everything into a common energy unit, like British Thermal Units (BTUs).

Formulas Used:

Total Heat Needed (BTU/Month) = Heating Requirement (BTU/Hour) × Daily Usage (Hours) × Monthly Usage (Days)

Electric Cost:

1. Energy Input Needed (kWh) = Total Heat Needed (BTU) / 3,412 BTU per kWh
2. Actual Energy Consumed (kWh) = Energy Input Needed / (Electric Efficiency % / 100)
3. Monthly Cost ($) = Actual Energy Consumed × Price per kWh

Gas Cost:

1. Energy Input Needed (Therms) = Total Heat Needed (BTU) / 100,000 BTU per Therm
2. Actual Energy Consumed (Therms) = Energy Input Needed / (Gas AFUE % / 100)
3. Monthly Cost ($) = Actual Energy Consumed × Price per Therm

Key variables in the gas vs electric heat cost calculation.

Variable	Meaning	Common Unit	Typical Range
BTU	British Thermal Unit, a measure of heat energy.	BTU/hour	20,000 – 100,000 for a home
kWh	Kilowatt-hour, a standard unit of electricity consumption.	$/kWh	$0.10 – $0.40
Therm / CCF	Units for natural gas volume/energy content.	$/therm or $/CCF	$1.00 – $3.00
AFUE	Annual Fuel Utilization Efficiency for gas furnaces.	Percentage (%)	80% – 98%
COP / Efficiency	Coefficient of Performance for electric heat pumps.	Percentage (%)	100% (resistance) to 400% (heat pump)

Practical Examples

Example 1: Cold Climate, Standard Efficiency

A homeowner in a cold region uses an older gas furnace and is considering switching to standard electric resistance heat.

• Inputs:
  • Electricity Price: $0.18/kWh
  • Gas Price: $1.20/therm
  • Heating Load: 50,000 BTU/hour
  • Usage: 10 hours/day, 30 days/month
  • Gas AFUE: 80%
  • Electric Efficiency: 100%
• Results:
  • Monthly Gas Cost: ~$225
  • Monthly Electric Cost: ~$791
  • Conclusion: In this scenario, natural gas is significantly cheaper.

Example 2: Moderate Climate, High-Efficiency Heat Pump

A homeowner in a milder climate compares a modern gas furnace to a high-efficiency air source heat pump.

• Inputs:
  • Electricity Price: $0.22/kWh
  • Gas Price: $2.00/therm
  • Heating Load: 30,000 BTU/hour
  • Usage: 6 hours/day, 30 days/month
  • Gas AFUE: 96%
  • Electric Efficiency (COP): 300%
• Results:
  • Monthly Gas Cost: ~$112.50
  • Monthly Electric Cost: ~$117.80
  • Conclusion: The costs are very close. A small change in energy prices could tip the balance. The high efficiency of the heat pump makes it competitive despite higher electricity unit prices.

How to Use This Gas vs Electric Heat Cost Calculator

1. Enter Energy Prices: Find the price per kilowatt-hour ($/kWh) for electricity and the price for natural gas (per therm or per CCF) from your most recent utility bills.
2. Define Heating Needs: Estimate your home’s heating requirement in BTU/hour. If unsure, 30-50 BTU per square foot is a common estimate. Then, input how many hours per day and days per month your system typically runs during the heating season.
3. Set Appliance Efficiencies: For electric heat, use 100% for baseboard/resistance heaters. For heat pumps, use the Coefficient of Performance (COP) as a percentage (e.g., a COP of 3.5 is 350% efficiency). For gas, use the AFUE rating listed on your furnace (e.g., 95%).
4. Interpret the Results: The calculator will instantly show the monthly and annual running costs for both options. The primary result will highlight which system is cheaper to operate based on your inputs. Use the chart for a quick visual comparison.

Key Factors That Affect Heating Costs

• Local Energy Prices: This is the most significant factor. The ratio of electricity to gas prices in your region will heavily influence the outcome.
• Climate: Colder climates require more BTUs and longer run times, amplifying the cost difference between systems.
• Appliance Efficiency: A high-efficiency heat pump (300%+ COP) can overcome high electricity prices, whereas a low-efficiency gas furnace (e.g., 80% AFUE) wastes significant energy.
• Home Insulation: A well-insulated and air-sealed home requires a lower heating load, reducing overall energy consumption for any system. Consider a home energy audit tool to identify improvements.
• Upfront Installation Cost: This calculator focuses on operational costs, but installation costs are a major factor. Gas furnaces and especially heat pumps can have high upfront costs.
• Maintenance Needs: Both systems require annual maintenance to operate at peak efficiency. These costs should be factored into the total cost of ownership.

Frequently Asked Questions (FAQ)

1. Which is generally cheaper, gas or electric heat?

Typically, natural gas is cheaper per unit of energy than electricity. However, the final cost depends heavily on appliance efficiency. A high-efficiency electric heat pump can be cheaper to run than an inefficient gas furnace, especially if the price of natural gas is high in your area.

2. What is the difference between a therm and a CCF?

Both are units for measuring natural gas. A therm is a unit of heat energy (100,000 BTU). A CCF is a unit of volume (100 cubic feet). They are very close, with 1 CCF of gas containing approximately 1.037 therms of energy. Our calculator lets you select which unit your bill uses.

3. What is AFUE?

AFUE stands for Annual Fuel Utilization Efficiency. It measures how much fuel a gas furnace converts to usable heat. An AFUE of 95% means 95% of the fuel becomes heat for your home, while 5% is lost, usually up the flue.

4. What is COP and how does it relate to efficiency percentage?

COP stands for Coefficient of Performance, used for heat pumps. It’s a ratio of heat output to electrical energy input. A COP of 3 means the heat pump produces 3 units of heat for every 1 unit of electricity consumed. This is equivalent to 300% efficiency. Heat pumps don’t create heat from electricity; they move it, which is why they can be over 100% efficient.

5. Does this calculator consider installation costs?

No, this is an operational cost calculator. It is designed to compare running costs based on fuel prices and efficiency. Installation costs vary widely by location, system type, and home specifics. You might use a furnace replacement cost calculator for that estimate.

6. When is a heat pump a better choice than a gas furnace?

A heat pump is often a better choice in moderate climates where temperatures don’t frequently drop below freezing, or in areas where natural gas is expensive or unavailable. They also provide cooling in the summer, combining two systems into one.

7. Why is my electric bill so high even with a heat pump?

If temperatures drop very low, your heat pump may switch to auxiliary “emergency” heat, which is simple electric resistance heating (100% efficient). This is much less efficient than the heat pump’s normal operation and can significantly increase costs. Also, incorrect sizing or poor insulation can force the system to run constantly.

8. Can I use this calculator for propane or oil heat?

This specific calculator is designed for natural gas and electricity. The principles are similar for propane and oil, but you would need to know the energy content per unit (e.g., BTUs per gallon) and your fuel price to adapt the formulas.