500 watts is great for up to 50 square feet, spaces like a desktop, cubicle, or bathroom. Think personal room use. 750 watts works well for a small office, small bedroom, or bathroom. 1000 watts should warm up large bathrooms, small living rooms, or a small room.
= 1000 watts total (3412 BTU/Hr). A 10' x 10' room would require 1000 watt baseboard.
For example, a 30-amp circuit can accommodate a baseboard heater rated for 500 square feet or 4,500 watts, but the same heater will be more efficient at heating a smaller room (assuming the circuit size is appropriate).
A 20x20 room with good insulation* would require a 4500W (15000 BTU/hr) heater to heat the room to 80°F.
The first technique is to simply figure the square footage of the space you want to heat. In warmer climates, multiply this number by 10 - 15. In more moderate climates, multiply by 20 - 30. And in cold climates multiply the square foot number by 30 - 40.
IDEAL FOR SMALL ROOMS: The 500W Brava Baseboard Heater is suitable for heating rooms up to 50 sq. ft., such as bedrooms, kitchens, or offices. DURABLE CONSTRUCTION: Built with a strong 22-gauge steel casing to ensure long-lasting performance.
Wattage: 400W. Volts: 120V. Room Capacity: Up to 120 Sq. Ft.
The maximum watts you can get in a 120 volt heater will be 1500 watts. Although they vary in size they produce the same amount of heat. As a rule of thumb it will require about 10 watts for every square foot. So the 1500 watt will usually heat up to 150 square feet.
Based on our research, ceramic and fan heaters are the best type of units for large spaces. More user-friendly than their infrared and oil-filled counterparts, they also heat up quickly, making them more effective than other options.
An average space heater can use anywhere from 500 to 1500 watts of electricity, depending on the size and type of heater. That means that it could take anywhere from one to five kilowatts of electricity to run a space heater, which is a significant amount of power.
The more insulation, the less wattage is needed to effectively heat the space. But with that said, you are going to need somewhere between 5-10 watts per square foot. And Home built within the last 10 years only require around 5 watts/sqft because of increased insulation standards in building codes.
For a 1 car garage with 200 sq ft to 300 sq ft, the estimated heater size is 15,000 to 25,000 BTUs. For a 2 car garage with 500 sq ft to 700 sq ft, the estimated heater size is 30,000 to 45,000 BTUs. For a 3 car garage with 750 sq ft to 900 sq ft, the estimated heater size is 45,000 to 55,000 BTUs.
This is because cold air can leak through and create unpleasant drafts. The heat from a baseboard heater under a window will rise and help to offset that cool air, the more cold air that comes in, the harder a heater has to work.
Room Size and Heater Wattage
As a rule of thumb, a well-insulated room requires around 100 watts per square metre for adequate heating. So, for a small room of 10m², a 1000W heater would do the job nicely. For a larger room of 20m², you'd need a 2000W heater to achieve the same level of warmth.
500 Watts – On average a 500-watt heater will cost 9.81p per hour and £0.59 per six hours. 750 Watts – Electric heaters with this wattage will cost approximately £0.94 to run for 6 hours or 15.70p per hour. 1,250 Watts – You can expect to pay 19.63p per hour running a heater with this wattage.
Using a space heater can be a good way to boost the temperature in a small, drafty room—and it could be less expensive than cranking up your central heating system. But a space heater is economical only if you use it judiciously.
For example, if you run a 500-watt device for 1 hour, it uses 0.5 kilowatt-hours (kWh). Multiply this by your electricity rate (e.g., $0.12 per kWh), and it would cost you about 6 cents. Over a month, if used for 8 hours daily, it could cost roughly $14.40.
Comfortably, and with an efficient on/off cycling rate about 400 sq. feet. That would be the “sweet spot” between comfort and efficiency. You could easily go to 500 sq.
Example (you can use an electric heater running cost calculator below for different wattages/kWh prices): If we assume the price of electricity is $0.1319 per kWh, a 1,500-watt electric space heater will cost; $0.20 to run per hour. $4.80 to run per 24 hours (day). $11.20 to run per week (8h/day).
1500 watts will heat spaces up to about 150 square feet and can help you stay warm and toasty in a medium-sized room, office, kitchen, or modest-sized living room.
In this case, if you have a room that measures 10 feet in length and 10 feet in width, the calculation would be straightforward. So, the equation would look like this: 10 feet (length) x 10 feet (width) = 100 square feet. This means that a 10x10 room is 100 square feet.
The average sized 2 car garage's square footage usually ranges from 400 (20×20), 576(24×24), and 720 (24×30) square feet.