CAA Habitation recommendedFree tool · Heating
Baseboard heater calculator, room by room
Enter the size of each room: the tool estimates the baseboard heater wattage to plan for using Stelpro’s recommendation for its BA series, 1.25 W per cubic foot or 10 W per square foot under an 8-foot ceiling, and what it asks of your panel, in amps at 240 V.
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Your rooms
Length, width and ceiling height, in feet.
Wattage to plan for
Total
3,440 W
14.3 A at 240 V
- Bedroom1,200 W5.0 A at 240 V · 4.8 ft of baseboard, roughly · one 3,000 W thermostat is enough
- Living room2,240 W9.3 A at 240 V · 9.0 ft of baseboard, roughly · one 3,000 W thermostat is enough
Stelpro’s wattage rule (BA series); length estimated at 250 W per foot (Sinopé); thermostats: maximum loads of Sinopé’s TH1123WF and TH1124WF. A ballpark figure, not a heat-loss calculation.
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The rule used
The manufacturer Stelpro recommends in the guide for its BA series baseboard a heating output of 1.25 W per cubic foot, which equals 10 W per square foot for an 8-foot ceiling. The tool therefore multiplies each room’s length, width and height by 1.25 W.
It’s a manufacturer’s recommendation, not a Code requirement. A room with a higher ceiling needs more: the rule is in cubic feet.
An example, room by room
A 12 by 10 foot bedroom under an 8-foot ceiling is 960 cubic feet: at 1.25 W per cubic foot, it needs about 1,200 W. At 240 V, that’s 5 A, and at 250 W per foot, about 4.8 feet of baseboard heater. One 3,000 W thermostat is enough. The calculator repeats this for each room you add, up to eight.
A 16 by 14 foot living room with the same ceiling is 1,792 cubic feet, or about 2,240 W and 9.3 A. Together, the two rooms need 3,440 W: more than the 2,880 W of a 15 A circuit under the 125% rule, so at least two circuits or a higher rating, which the electrician confirms.
How many baseboard heaters on one circuit
According to the Régie du bâtiment du Québec’s interpretation (Chapter V of the Construction Code, 2010 edition), a branch circuit that supplied a fixed heating appliance couldn’t supply other appliances, and with a breaker approved for 80% continuous duty, the protection had to be at least 125% of the load current; later editions were not reviewed for this tool.
For example, on a 15 A breaker: 15 A ÷ 1.25 = 12 A, or 2,880 W at 240 V. The 2026 edition of Chapter V is now in force: the electrician checks the actual rating of each circuit, subject to the exceptions in the Code.
The thermostat follows the wattage
A thermostat controls the total of the heaters connected to it: Sinopé says to add up their wattage. Its TH1123WF and TH1124WF baseboard thermostats control at most 3,000 W and 4,000 W at 240 V, resistive loads only, and at least 500 W.
Sinopé specifies that installation must be done by a certified electrician. We install Sinopé models and Hilo-compatible thermostats: see Hilo thermostat installation and our baseboard heaters and thermostats.
What it asks of your panel
A new baseboard heater means a new circuit or an extra load on an existing circuit. To find the amps, divide the watts by the voltage: baseboard heaters run on 240 V. See our watts to amps calculator and the electrical load calculation.
In winter
In very cold weather, heating can account for up to 80% of a home’s electricity use, according to Hydro-Québec.
A slight crackling when it starts is often normal: it’s the metal expanding. For its BA series, Stelpro also notes that a smell and a thin whitish smoke are normal the first time it’s turned on or after a long period off. An unusual smell that persists isn’t: Québec.ca says to call a master electrician.
To keep baseboard heaters running during an outage, the generator size calculator counts them by the foot, and the winter electrical checklist lists the clearances to check.
Clearances and safety
For its BA series, Stelpro asks you to leave at least 15 cm (6 in) between the top of the baseboard and furniture, curtains, blankets or clothing: an obstruction would cause overheating, which could start a fire. Québec’s Ministère de la Sécurité publique (Ministry of Public Security) gives the same 15 cm distance for wall heaters.
Before dusting it, switch off its power at the breaker, as Stelpro’s BA series guide asks.
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Frequently asked questions
How many watts does it take to heat a room?
For its BA series, Stelpro recommends 1.25 W per cubic foot, or 10 W per square foot for an 8-foot ceiling: a 12 ft by 10 ft bedroom therefore needs about 1,200 W. It’s a manufacturer’s rule, a starting point, not a Code requirement.
How many baseboard heaters can go on one breaker?
It depends on their wattage and the circuit’s rating. According to the RBQ’s interpretation (2010 edition of Chapter V; later editions were not reviewed), with a breaker approved for 80% continuous duty, the protection had to be at least 125% of the load current: a 15 A breaker therefore carried at most 12 A, or 2,880 W at 240 V. An electrician checks the actual rating of your circuits.
What length of baseboard heater for 1,000 W?
It depends on the model’s density. Sinopé estimates a baseboard at 250 W per foot at 240 V, so 4 feet for 1,000 W; Stelpro’s ALC1B mini baseboard is 150 W per foot. The exact wattage is on the heater’s label.
My baseboard heater smells like burning at the first cold snap: is that normal?
At first, yes: for its BA series, Stelpro writes that a smell and a thin whitish smoke are normal the first time it’s turned on or after a long period off. If the smell persists, switch the heater off at the breaker and call a master electrician, as Québec.ca recommends for an unusual smell.
Sources
- Stelpro, BA series baseboard user guide (recommended output, clearances) (in French)
- Stelpro, ALC1B series mini baseboard user guide (in French)
- Sinopé, smart thermostat for electric baseboard heaters (TH1123WF, TH1124WF) (in French)
- Régie du bâtiment du Québec, branch circuits for fixed heating equipment (2010 Code) (in French)
- Ministère de la Sécurité publique (Québec’s Ministry of Public Security), 10 electrical safety tips (2026) (in French)
Sources consulted on November 5, 2026.
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