Gas vs Electric Cost Comparison

The Gas vs Electric Cost Comparison tool tells you whether natural gas or electricity is cheaper to run for heating, hot water, cooking, or drying. Because the two fuels are sold in different units and convert energy at very different efficiencies, comparing the headline price is misleading. This tool puts both on the same footing — cost per useful kWh delivered — and then shows your daily, monthly and annual cost, the cheaper option, the break-even prices where the two are equal, and a CO₂ emissions comparison.

How the Gas vs Electric Comparison Works

The honest way to compare two fuels is to look at the cost of the energy that actually reaches the room, the water, or the food — the useful energy. That means dividing the fuel price by both the energy content of the unit and the appliance efficiency.

Whichever number is smaller is the cheaper fuel for that task. Multiply by the useful energy you use per year to get the annual cost.

Natural Gas Energy Content by Unit

Gas bills around the world use different units. These are the useful energy values this tool uses to convert a gas price into a price per kWh.

Typical Appliance Efficiencies

Efficiency is the key reason gas and electric costs diverge. Note that heat pumps exceed 100% because they move existing heat rather than generate it.

When Is Gas Cheaper Than Electric?

Gas usually wins when electricity prices are high and you are comparing against a basic electric resistance appliance (a standard electric heater, coil stove, or resistance water heater), because resistance electricity is at best 100% efficient while delivering each kWh at the full retail rate. Electricity wins when you run a heat pump — its 250–400% efficiency often more than offsets a higher per-kWh price — or when local electricity is cheap relative to gas (for example with solar, off-peak tariffs, or a low-carbon grid). The break-even prices in your results show exactly where the balance tips.

What Affects the Result?

How to Use This Calculator

1. Choose what you are comparing: Pick the appliance and currency. Typical efficiencies are filled in for you and can be edited.
2. Enter your energy use: The useful energy delivered per day in kWh, and how many days a year you use it.
3. Enter prices and efficiencies: Your gas price and unit, electricity price per kWh, and each system's efficiency.
4. Click Compare: See the cheaper fuel, cost per useful kWh, daily/monthly/annual cost, break-even prices, and annual CO₂.

Frequently Asked Questions

Is gas or electric cheaper to run?

It depends on local prices and appliance efficiency. Historically natural gas has been cheaper per unit of heat, but high-efficiency electric heat pumps deliver 250 to 400 percent efficiency and can beat gas. This tool compares both on a cost-per-useful-kWh basis so you can see which wins for your prices.

What is cost per useful kWh?

It is the price you actually pay for each kWh of heat or work delivered, after accounting for efficiency. It equals the fuel price divided by the energy content of the unit times the efficiency. Comparing fuels this way is fair because gas and electric appliances convert energy at very different rates.

How do I convert gas prices to compare with electricity?

Natural gas is sold in therms, ccf, cubic metres, kWh or MMBTU. One therm equals about 29.3 kWh, one ccf about 30.4 kWh, one cubic metre about 10.55 kWh, and one MMBTU about 293 kWh. Divide the gas price by these figures and by the appliance efficiency to get a cost per useful kWh that you can compare directly with electricity.

Why can electric efficiency be over 100%?

Heat pumps do not create heat, they move it from outside to inside, so they deliver more heat energy than the electricity they consume. A heat pump with a COP of 3 is 300 percent efficient. Resistance heaters, electric stoves and standard water heaters are at or below 100 percent.

What is the break-even price?

The break-even electricity price is the rate at which electricity would cost the same as gas, given your gas price and efficiencies. If your real electricity price is below it, electricity is cheaper. The tool also shows the break-even gas price the same way.

Does this include CO2 emissions?

Yes. Burning natural gas releases about 0.181 kg of CO₂ per kWh of gas. Electricity emissions depend on your grid, so the grid carbon intensity is an editable input that defaults to about 0.37 kg per kWh. The tool shows annual CO₂ for both options and which is greener.

Additional Resources

• Heat of Combustion - Wikipedia
• Coefficient of Performance (Heat Pumps) - Wikipedia