What this calculator does
The Gas vs Electric Dryer Calculator compares the yearly running cost of an electric clothes dryer against a natural-gas dryer. It accounts for how many loads you run, your local electricity and gas prices, and the small amount of electricity a gas dryer still uses for its motor, controls and igniter.
How to use it
Enter your loads per week and weeks per year to get total annual loads. Add the electric dryer's energy use per load (kWh), your electricity rate ($/kWh), the gas dryer's gas use per load (therms), your gas rate ($/therm), and the gas dryer's auxiliary electricity per load. The tool returns both annual costs, the cheaper option, and your yearly savings.
The formula explained
Electric cost = kWh per load × electricity rate × total loads. Gas cost = (therms per load × gas rate × total loads) + (auxiliary kWh per load × electricity rate × total loads). The difference is the absolute gap between the two annual totals.
$$\Delta = \left| C_{\text{elec}} - C_{\text{gas}} \right|$$
$$\text{where}\quad \left\{ \begin{aligned} N &= \text{Loads/wk} \times \text{Weeks/yr} \\ C_{\text{elec}} &= \text{kWh/load} \times \text{Elec rate} \times N \\ C_{\text{gas}} &= \left(\text{Therms/load} \times \text{Gas rate}\right) N + \left(\text{Aux kWh} \times \text{Elec rate}\right) N \end{aligned} \right.$$
Worked example
\(5 \text{ loads/week} \times 52 \text{ weeks} = 260 \text{ loads}\). Electric: $$3.3 \text{ kWh} \times \$0.16 \times 260 = \$137.28.$$ Gas: $$0.22 \text{ therms} \times \$1.20 \times 260 = \$68.64,$$ plus aux $$0.1 \text{ kWh} \times \$0.16 \times 260 = \$4.16,$$ totaling \(\$72.80\). Gas wins, saving about \(\$64.48\) a year.
FAQ
Why does a gas dryer still use electricity? The drum motor, blower, lights and electronic igniter run on household current even though heat comes from gas.
What is a therm? A therm is a unit of heat energy equal to 100,000 BTU, the standard billing unit for natural gas in the US.
Are installation costs included? No — this compares running costs only. Gas dryers cost more upfront and may need a gas line and venting, which you should weigh against the energy savings.
