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What size electric heater for 20 m²?

How many watts you need, what running it costs, and when electric heating stops making sense.

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Small roomsSchmidbauer Hybrid Pro 600 WBathroom-capableSchmidbauer ISP T 700 WFast heatMidea NTH20-17BRAll models with reasoning ↓

🗓 Updated August 28, 2026 · EcoBack editorial team

Heating a room of around 20 m² with an electric panel or infrared heater? It works — but only with the right wattage and honest expectations about the electricity bill. Here is the concrete recommendation for 20 m².

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Quick answer: For 20 m² you need about 1,200–1,600 W of heating power (rule of thumb: 60–100 W per m², depending on insulation). At full power that costs about €0.42 per hour at €0.30/kWh — a thermostat brings the real-world figure well down.
Recommended models

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Compiled from public tests & customer reviews — not tested by us. Prices vary; check the current price on Amazon. Illustrations, not product photos. One thing first: size the wattage to the room (60–100 W per m² depending on insulation) and let a thermostat cycle it — running flat out is the expensive mistake. Amazon.de ships to most EU countries, with site and checkout available in English.

Small rooms

Schmidbauer Hybrid Pro 600 W

Infrared plus convection with a stepless thermostat; the manufacturer names 6–12 m² as its range.

€€ · check price locally
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Bathroom-capable

Schmidbauer ISP T 700 W

700 W and rated by the manufacturer for damp rooms — the answer to bathroom heating without running a fan heater for hours.

€€ · check price locally
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Fast heat

Midea NTH20-17BR

Ceramic fan heater with two stages (1,200 / 2,000 W) — for quick warm-ups, not for continuous heating.

€ · check price locally
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How many watts for 20 m²?

From 20 m² upwards, 1,200–1,600 W makes sense. Two panels often spread the heat better than one. Well-insulated new buildings sit at the lower end of the 60–100 W per m² band, old buildings with high ceilings at the upper end.

The full size ladder

Room sizeHeating powerTypical room
10 m²600–800 Wsmall office or bathroom
15 m²900–1,200 Whome office or small living room
20 m² (this page)1,200–1,600 Wliving room or bedroom
25 m²1,500–2,000 Wlarger living room
30 m²1,800–2,400 Wopen-plan living area
40 m²2,400–3,200 Wvery large or open-plan room
50 m²3,000–4,000 Wvery large open area
Electric heating · 1,200–1,600 W

An infrared panel (or set of panels) totalling 1,200–1,600 W with a thermostat fits a living room or bedroom. The thermostat is where the saving is — it cycles the panel instead of heating continuously. We do not test units ourselves; picks summarise public tests.

✓ No installation, plugs into a socket   ✓ Silent, no moving parts   ✕ Electricity is an expensive way to make heat

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What does heating 20 m² cost?

At full power, 1,400 W draws about €0.42 per hour (calculated at €0.30/kWh — put in your own tariff). For a season: with 5 heating hours a day, a thermostat duty cycle of about 40 % and 150 heating days that is roughly €126 per season. The formula is transparent: watts ÷ 1000 × price × hours × duty cycle × days. Electric resistance heating turns one kilowatt-hour of electricity into exactly one kilowatt-hour of heat — that physics is why a heat pump beats it for whole-home, all-winter heating.

Frequently asked questions

How many watts of heating power do I need for 20 m²?
As a rule of thumb 1,200–1,600 W (around 60–100 W per m², depending on insulation). From 20 m² upwards, 1,200–1,600 W makes sense. Two panels often spread the heat better than one.

What does heating with 1,400 W cost?
At full power a 1,400 W heater draws about €0.42 per hour (at €0.30/kWh). A thermostat lowers that considerably, because it does not heat continuously.

What does a heating season cost for 20 m²?
With 1,400 W, 5 heating hours a day, a thermostat duty cycle of about 40 % and 150 heating days you end up at roughly €126 per season (at €0.30/kWh). Recalculate with your own tariff: watts ÷ 1000 × price × hours × duty cycle × days.

Is an electric panel heater enough as the only heating for 20 m²?
As a supplementary or transition-season heater, yes. As the sole heating in deep winter, a building heat pump is usually more economical — electric resistance heating turns every kilowatt-hour of expensive electricity into exactly one kilowatt-hour of heat, no more.

Matching heating panels for 20 m² on Amazon.de — check total wattage and the thermostat:

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