How this instrument works
Both gas and electric dryers use an electric motor to tumble the drum — that part of the cost is identical in kind, if not always in wattage, between the two types. The real difference is the heat source: an electric dryer heats with a resistive electric element, drawing significant additional wattage from the same electric bill, while a gas dryer heats by burning natural gas, billed separately in therms, alongside its own smaller electric motor draw.
To compare the two on equal footing, this calculator converts the gas dryer's BTU-per-hour heating rating into therms — the standard natural gas billing unit, where 1 therm equals 100,000 BTU — then prices that against your entered gas rate, while pricing the electric-only dryer's full wattage against your entered electricity rate. Both dryer types' costs scale with the same cycle length and weekly load count, so the comparison isolates the energy-source difference rather than assuming a fixed 'gas is cheaper' answer.
This is a first-principles cost model built from your own wattage, BTU, and price inputs, not a fixed national average — actual results depend heavily on your local utility rates, so pulling your own per-kWh and per-therm prices from a recent bill will give a far more accurate comparison than leaving the defaults untouched.
- Enter your typical drying cycle length in minutes and how many loads you run per week.
- Enter your electric dryer's wattage and your price per kilowatt-hour.
- Enter your gas dryer's tumble-motor wattage, its BTU heating rating, and your price per therm.
- Compare the two annual cost outputs side by side.
Worked example — 45-minute cycles, 5 loads a week
Electric dryer, 5,000 W, $0.15/kWh: (5,000 × 0.75 ÷ 1,000) × 0.15 = $0.5625 per cycle. Over 5 loads a week, 52 weeks a year: $0.5625 × 5 × 52 = $146.25 a year.
Gas dryer, 500 W tumble motor, 20,000 BTU/h, $0.15/kWh and $1.20/therm: motor cost (500 × 0.75 ÷ 1,000) × 0.15 = $0.05625, plus heating cost (20,000 × 0.75 ÷ 100,000) × 1.20 = $0.18, for $0.23625 per cycle. Over the same 5 loads a week: $0.23625 × 5 × 52 = $61.425 a year — well under half the electric dryer's annual cost in this example, though the gap depends heavily on your local gas and electricity prices.
Questions
Why do gas dryers still use electricity at all?
The heating element in a gas dryer burns natural gas, but the drum still needs to tumble the clothes, and that tumbling motor runs on electricity in both gas and electric dryers alike. A gas dryer's electric draw is typically much smaller than an all-electric dryer's, since it only powers the motor rather than also generating heat.
What is a "therm" and why does the formula use it?
A therm is the standard billing unit for natural gas, equal to 100,000 British thermal units (BTU) — utility companies price gas by the therm the way electricity is priced by the kilowatt-hour. Since gas dryers are rated in BTU per hour, converting that heating rate into therms is necessary to price it against your actual gas bill's per-therm rate.
Is a gas dryer always cheaper to run than an electric one?
Not necessarily — it depends heavily on your local electricity and natural gas prices, which vary significantly by region and utility. Natural gas is often, but not always, the cheaper energy source per unit of heat delivered; entering your own actual utility rates into this calculator, rather than relying on national averages, gives the most accurate comparison for your situation.
Where do I find the wattage and BTU rating for my own dryer?
Both figures are typically printed on a rating label or plate on the dryer itself (often inside the door frame or on the back panel), or listed in the appliance's owner's manual or manufacturer spec sheet — search the model number online if the physical label has worn off or isn't accessible.
Does this calculator include the upfront cost of installing a gas line?
No — this calculator only compares ongoing operating costs based on energy use, not one-time installation costs like running a new gas line, venting requirements, or the price difference between the two dryer types themselves. Factor those separately into a full cost comparison if you're deciding which type to install from scratch.