The normal range
A plug-in electric heater is limited by the socket it plugs into. In countries on 110–120 V, a standard circuit gives you about 1,500 watts, and that is what almost every plug-in heater sold there draws at full power. In countries on 220–240 V, the same socket can supply more, and heaters there are commonly 2,000 watts, sometimes up to 3,000.
Small "personal" plug-in heaters — the ones the size of a bread bin — are often 400 to 800 watts and are honest about being for one desk rather than one room.
There is no plug-in heater that draws less and heats more. The socket is a hard ceiling, and inside that ceiling the wattage is the heat.
Why sellers leave it out
Because the number is unflattering to the marketing. A heater advertised as the answer to a high heating bill looks very different once you can see that it draws 1,500 watts — about the same as ten old-fashioned light bulbs running continuously, or roughly what a kettle draws, except a kettle runs for three minutes and a heater runs all evening.
It also makes coverage claims checkable. The heating trade works to a rough guide of 60 to 100 watts per square metre for supplementary electric heat, depending on insulation, ceiling height and climate. Once you know the wattage, you can do that division yourself:
- 1,500 W ÷ 100 W/m² = 15 m² in a draughty room
- 1,500 W ÷ 60 W/m² = 25 m² in a well-insulated one
- 2,000 W ÷ 80 W/m² = 25 m² in a typical European room
Which is why a plug-in heater advertised as covering 50 m² deserves a raised eyebrow, and why the seller who advertises it tends not to print the wattage next to it.
What to do before you buy
If the wattage is not on the product page, ask for it in writing before you order, and keep the answer. Ask for the voltage at the same time — the two together tell you whether the unit is usable in your country and what it will cost you per hour.
If the seller will not answer either question, that is itself an answer about how much of the rest of the page you should rely on.
Frequently asked questions
Is a 1500 W heater better than a 1000 W one?
It produces more heat, and it costs proportionally more to run. Neither is more efficient — all electric resistance heaters convert essentially 100% of the electricity they draw into heat. The right wattage is the one that matches your room.
Do ceramic or PTC heaters use less electricity?
No. Ceramic, PTC, oil-filled, panel and fan heaters of the same wattage all deliver the same heat for the same electricity. What differs is how quickly the heat is distributed and how the unit feels to live with, not efficiency.
Can I run two plug-in heaters on one circuit?
Often not. Two 1,500 W heaters on one 15 A / 120 V circuit will exceed it. Spread them across circuits and never run a heater through a light-duty extension lead.
Sources
- Directive 2006/114/EC on misleading and comparative advertising.
- Heatoor, WellHeater and VelaWarm product pages — checked 12 September 2026 for a published power rating; none found.