Best Electric Garage Heater 120V: Size Guide | Curb Calc

A 1,500 W plug-in heater warms a bench, not a two-car garage. Watts by garage size, cost per hour, the gas-can rule in every manual, three picks.

11/7/20264 min read

Curb Calc cover titled Best Electric Garage Heater, with a photo of a glowing heater element, a FREE CALCULATOR badge, a callout that a 24x24 two-car garage needs 5,760 W at 10 W per sq ft while one plug-in heater is 1,500 W, and a table of watts at 10 and 15 W per sq ft for 1-car 12x20, 2-car 20x20 and 2-car 24x24 garages.Curb Calc cover titled Best Electric Garage Heater, with a photo of a glowing heater element, a FREE CALCULATOR badge, a callout that a 24x24 two-car garage needs 5,760 W at 10 W per sq ft while one plug-in heater is 1,500 W, and a table of watts at 10 and 15 W per sq ft for 1-car 12x20, 2-car 20x20 and 2-car 24x24 garages.

The mower's gas can, a shelf of leftover paint, and a new space heater: the Vornado, Dura Heat and Dr. Infrared manuals all say those don't belong in the same room. Clear them out first. Then size it: a 120 V heater is 1,500 W, spot heat for a bench, not a garage.

Quick pick: the Dr. Infrared DR-268, mounted high, away from gas cans and wet floors (electrician install per its manual). Plug-in for a dry garage, on the floor near the bench: the Dura Heat EUH1500, though its manual says avoid damp garages.

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A red metal shelf crowded with paint cans, buckets and spray cans against a concrete wall in a workshop
A red metal shelf crowded with paint cans, buckets and spray cans against a concrete wall in a workshop

Photo: Orlando García on Unsplash

Clear the gas and paint first

All three manuals: heaters have hot, arcing or sparking parts, so don't use one where gasoline, paint or flammable liquids are used or stored.

Fewer gas cans: run the push mower dry for winter; see how to winterize a lawn mower.

3 feet: the U.S. Fire Administration says keep anything that can burn at least 3 feet from a space heater.

Snow falling in front of a closed dark blue sectional garage door
Snow falling in front of a closed dark blue sectional garage door

Photo: Kelly Sikkema on Unsplash

What size heater for a 1- or 2-car garage

Broan-NuTone's rule: 10 watts per square foot for supplemental heat, 15 W if it's the only heat or the room is poorly insulated.

12x20 one-car (240 sq ft): 2,400 W at 10 W, 3,600 W at 15 W.

20x20 two-car (400 sq ft): 4,000 W, or 6,000 W.

24x24 two-car (576 sq ft): 5,760 W, or 8,640 W.

One kWh is 3,412 BTU (EIA), so a 1,500 W heater makes about 5,118 BTU an hour. Dura Heat rates the EUH1500 for up to 250 sq ft; Dr. Infrared lists 150 to 200 for the DR-268.

Our read: 120 V is spot heat: a bench, or the chill off a small insulated bay. A whole two-car garage needs a 240 V hardwired unit, an electrician job. Outdoors? See patio heater sizes.

The glowing orange heating element of an electric heater behind its grille in the dark
The glowing orange heating element of an electric heater behind its grille in the dark

Photo: Achudh Krishna on Unsplash

Cost to run

At 18.16 cents per kWh, the U.S. home average for August 2026 (EIA), 1,500 W costs about 27 cents an hour: $1.09 for four hours, $2.18 for eight. That's nonstop on high; a thermostat cycles off.

Close-up of the two control knobs on a black space heater with a Do Not Cover label
Close-up of the two control knobs on a black space heater with a Do Not Cover label

Photo: Donald Teel on Unsplash

Setup rules from the manuals

Wall outlet only: all three say plug directly into a wall outlet, never an extension cord or power strip. Cords are for lights.

One per circuit: 1,500 W at 120 V is 12.5 A (all three listings), so two heaters pull 25 A. Dura Heat says not to put another appliance on its circuit.

GFCI outlet? Code (NEC 210.8) requires GFCI on garage outlets (IAEI), so yours likely has one. Vornado's guide says not to use its heater on a GFCI outlet; skip that pick if so. Never bypass a GFCI.

Dry spot only: Dura Heat's manual lists garages, like flooded basements, as damp areas to avoid. Wet floor or snowmelt? Skip it.

Leaving? USFA: turn it off when you leave the room or go to bed.

Mounting the DR-268: its manual wants a qualified electrician, at least 94.5 in up (about an 8.5-ft ceiling), 39.4 in from wood or cloth.

A pegboard wall of hand tools and a fire extinguisher above a wooden workbench in a home garage workshop
A pegboard wall of hand tools and a fire extinguisher above a wooden workbench in a home garage workshop

Photo: btwashburn on Wikimedia Commons (CC BY 2.0), cropped

120V garage heaters (#ad)

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Dr. Infrared DR-268 Heater with Thermostat: 1,500/1,000 W infrared, wall or ceiling mount, temperature probe, ETL certified, per the listing. See it on Amazon

Dura Heat EUH1500 Forced Air Heater: 1,500 W, 5,120 BTU, thermostat, up to 250 sq ft, per the listing; dry spots only, per its manual. See it on Amazon

Vornado Velocity HD (2026) Garage Space Heater: 1,500 W, tilt head, tip-over protection, cool-touch case, per the listing; its guide says no GFCI outlet. See it on Amazon

A man in a quilted vest bent over a small engine on a workbench, seen through an open sliding glass door of a workshop
A man in a quilted vest bent over a small engine on a workbench, seen through an open sliding glass door of a workshop

Photo: Josip Ivanković on Unsplash

Garage heater FAQ

Can a 120V heater heat a 2-car garage?

Not by Broan-NuTone's rule. A 24x24 garage needs 5,760 W, almost four 1,500 W heaters.

Can I leave a garage heater on overnight?

No. USFA says turn heaters off at bedtime.

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Sources: IAEI NEC 210.8; Vornado guide; Dura Heat EUH1500 manual; Dr. Infrared DR-268 manual; Broan-NuTone sizing; USFA heating safety; EIA Table 5.6.A; EIA Btu.