Small sheds are easier to heat than larger workshops, but choosing the right heater still matters. Too much power wastes energy, and too little power leaves the space uncomfortable.
This guide explains the best electric heater options for sheds under 100 square feet.
How Much Heat Does a Small Shed Need?
Start by calculating square footage.
For sheds under 100 sq ft, use this rule:
Insulated shed
10 watts per square foot
Uninsulated shed
12–15 watts per square foot
Example:
8×8 shed (64 sq ft) insulated
64 × 10 = 640 watts
In most small sheds, a 750–1,500 watt heater is sufficient.
If you need help calculating, see How Many Watts to Heat a Shed?
Best Heater Types for Small Sheds
Portable Electric Heaters
Portable heaters are often the simplest solution.
They:
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Plug into standard 120V outlets
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Require no installation
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Are easy to move or store
Most portable models max out at 1,500 watts, which is typically enough for small insulated sheds.
For more detail, see Best Portable Electric Heater for a Shed.
Wall Mounted 120V Heaters
If you want a permanent setup, a compact wall-mounted heater is a good option.
Benefits include:
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Freeing up floor space
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More consistent airflow
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Cleaner installation
See Best 120V Electric Heater for a Shed for examples.
When a Small Shed May Need More Power
Even under 100 sq ft, you may need closer to 1,500 watts if:
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The shed is uninsulated
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Winter temperatures drop below freezing
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The shed has frequent door openings
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Ceiling height is above 8 feet
If insulation is minimal, review Best Electric Heater for an Uninsulated Shed.
Electrical Considerations
Small sheds typically run on standard 120V circuits.
Before installing:
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Avoid using extension cords
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Ensure the outlet is not overloaded
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Confirm breaker capacity
If you are unsure about circuit limits, see Do You Need a Dedicated Circuit for a Shed Heater?
Safety in Small Spaces
Because small sheds have limited space, heater placement is important.
Maintain:
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Proper clearance from walls
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Distance from stored wood or cardboard
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Unblocked airflow
Choose models with overheat protection and thermostat control.
For additional guidance, see Is It Safe to Run an Electric Heater in a Shed?
Final Thoughts
For sheds under 100 sq ft, the best electric heater is usually:
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750–1,500 watts
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120V plug-in
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Portable or compact wall-mounted
Sizing correctly and ensuring safe placement will keep the space comfortable without excessive energy use.
For a broader overview of shed heating options, see Best Electric Heater for a Shed (Complete Buyer Guide).