Updated October 2026.
Most people who ask us to help them choose a room heater walk in knowing the brand they like and the price they'd rather not cross. Very few walk in knowing the size of the room. We ask, and the answer is usually a hand waved in the air and "normal size, a bedroom". That's the moment we pull out the bill book and start drawing.
Because the size of the room is the whole job. Get it right and almost any decent heater does well. Get it wrong and the best badge in the shop either can't keep up or roasts you out of the room. So this is the checklist we run through with people at the counter, in the order we run it: the room, the watts, the fins, the features, the socket and the safety marks. Then five heaters, one for each size of room we're asked about.
How do you choose a room heater?
Measure the room, multiply its square feet by 10 to get the watts you need, then pick the type by how long you'll sit in it, and only then look at features and brands. That order saves most people from the two mistakes we see every winter, which are buying too small and buying too big.
People ask us which heater is best when what they mean is which heater will keep this particular room warm without a shock on the bill. Those have different answers, and the second one starts with a tape measure. A 10 by 12 bedroom and a 16 by 18 drawing room need heaters that are nearly three times apart in output. No amount of brand reputation closes that gap.
Here's the full checklist, and we'll take each step in turn below.
- The room. Length times breadth in feet.
- The watts. Roughly 10 watts for each square foot.
- The type. Fan heater for minutes, halogen for one person in one spot, oil-filled for an evening or a night.
- The controls. A real thermostat, not just heat settings.
- The socket. Anything big needs a 16 amp point on the wall.
- The safety marks. A tip-over switch, an overheat cut-out and the ISI mark.
If you're still torn between types, our guide to the best room heater for home walks through fan, halogen and oil-filled side by side, along with running costs and the safety points for sleeping rooms. This page stays on the size question, because that's the one people skip.
What size room heater do I need for my room?
About 10 watts for every square foot of floor, so a 10 by 12 bedroom of 120 sq ft wants a heater that can deliver around 1,200 W. It's the figure manufacturers and retailers most often suggest, as Ontario's Save on Energy programme puts it in its heater buying guide (Save on Energy, IESO).
Here's how that works out for the rooms we hear about most. Watts are rounded, and they're what you want the heater to manage on a cold night, not necessarily its top setting.
| Room | Floor area | Watts at 10 per sq ft | What usually fits |
|---|---|---|---|
| 8 by 10, small study | 80 sq ft | about 800 W | A halogen on its top setting, or a fan heater on low |
| 10 by 12, standard bedroom | 120 sq ft | about 1,200 W | A 9 fin oil-filled radiator on its middle step |
| 12 by 14, master bedroom | 168 sq ft | about 1,700 W | A 9 or 11 fin radiator |
| 14 by 16, living room | 224 sq ft | about 2,250 W | An 11 or 13 fin radiator, 2,500 W or more |
| 16 by 18, drawing room | 288 sq ft | about 2,900 W | A 2,900 W radiator running near full output |
| Bigger than that | 300 sq ft plus | 3,000 W and up | Two heaters, or a hot and cold AC |
Two honest caveats, because this rule wasn't written for Delhi. The guide we've quoted is Canadian, written for insulated homes and far harsher winters. Our brick and concrete flats have no insulation to speak of, which pushes the number up. Our winters are much milder, which pulls it down. In practice we treat 10 watts a square foot as the starting point and then adjust for the room in front of us. A corner room with two outside walls, a top floor flat under a bare roof or a ground floor that never sees the sun all want a step more. A middle floor bedroom with one window can get away with a step less.
Ceiling height matters too, and it's the step people forget when they choose a room heater from a floor plan. The rule assumes an ordinary ceiling. Tall ceilings mean more air to warm, so size up.
Can you trust the room size printed on the box?
Treat it as a rough guide at best, because two heaters with the same watts and the same fins can claim very different room sizes. We'd always size on watts, which are measured, rather than square feet, which are a claim.
Here's an example from our own range that surprises people when we show them. The Glen HA7013DOR is an 11 fin, 2,900 W radiator and its listing says it covers up to 250 sq ft. The Morphy Richards Heat Wave 11F is also an 11 fin, 2,900 W radiator, and its listing says up to 150 sq ft. Same fins, same watts, and a hundred square feet apart on the box.
None of those figures is a lie. Each brand is assuming a different room, a different starting temperature and a different idea of warm enough. That's exactly why we'd never choose a room heater off the carton. Two heaters with the same watts put the same heat into your room, whatever the carton says.
9 fin vs 11 fin vs 13 fin: does the number of fins matter?
Less than you'd think, because the watts decide how much heat you get and the fins decide how it's spread and how long it lingers. A 13 fin radiator and an 11 fin radiator that are both rated at 2,900 W make the same amount of heat while they're running.
This is the question we're asked most in the oil-filled aisle, usually by someone who's been told more fins means more heat. Look at a pair with the same element and the picture's clearer. The Bajaj Vienna 11 fin and the Bajaj Vienna 13 fin are both 2,900 W. Same heat in. What the two extra fins buy you is more metal and more oil.
More surface means each fin runs a little cooler for the same output, so the heat comes off gentler and spreads more evenly. More oil means more stored warmth, so the room holds its temperature longer after the thermostat switches the element off. And in that particular pair, the 13 fin carries a three year warranty against two on the 11. Those are fair reasons to pay a little more. Heating a bigger room isn't one of them, unless the watts go up too.
So if you choose a room heater by counting fins, you're counting the wrong thing. Check the watts first and the fins second. A 9 fin at 2,400 W and a 13 fin at 2,900 W are a different size of heater. An 11 fin and a 13 fin at the same 2,900 W are the same size of heater in different clothes.
Which features are worth paying more for?
A real thermostat first, sensible heat steps second, and a PTC fan or a timer after that. Those are the three that change how the heater behaves every night. Most of the rest is finish, and it's the last thing to weigh when you choose a room heater.
- Thermostat. It switches the element off when the room reaches your setting and back on when it cools, so the heater isn't running flat out for hours. Save on Energy makes the same point, that an adjustable thermostat stops the heater wasting energy running when it doesn't need to (Save on Energy). We'd give up almost anything else on the spec sheet before this.
- Heat steps. Three steps such as 1,000, 1,500 and 2,500 W let a big heater behave like a small one on a mild evening. That's what makes buying one size up safe.
- PTC fan. A small ceramic fan heater, usually 400 W, built into an oil-filled radiator. It takes the chill off in the first few minutes while the oil comes up to temperature, which answers the one complaint everybody has about radiators.
- Timer and remote. Worth paying for if you warm a bedroom before sleep, because the timer switches it off after you've dropped off. A remote matters more than people expect for an older parent who'd otherwise bend down to the dial in the dark.
- Warranty length. In our heater range it runs from one year to three. On an appliance you'll store for most of the year and pull out every winter, the longer one is worth having.
One correction we owe readers of the older version of this page. It told you to look for an energy efficient heater because "the more energy efficient the room heater is, the lower your energy bills will be". That's not right, and we'd rather fix it than leave it standing. Any electric heater turns all the electricity it uses into heat (Save on Energy). There's no efficient model to hunt for. What lowers the bill is fewer watts for fewer hours, and that's the thermostat's job.
Are heat settings the same as a thermostat?
No, and this is the most common mix-up we see on the shop floor. Heat settings choose how hard the heater runs. A thermostat decides when it stops.
A heater with three settings and no thermostat will run at whatever step you pick until you switch it off, even once the room's warm. A heater with a thermostat will hold the room near the temperature you've set and cycle itself on and off. Some radiators in our own range list three heat levels and don't list a thermostat at all, and we'd rather you knew to check than found out in January.
The quick test when you're looking at a heater: ask whether there's a dial or button that sets a temperature, separate from the one that sets the power. If there's only one, it's probably just settings.
Which safety features should a room heater have?
A tip-over switch, an overheat cut-out and a safety certification mark, which in India means the ISI mark. Save on Energy recommends tip-over and automatic shut-off features (Save on Energy), and the US Consumer Product Safety Commission tells buyers to look for a safety certification mark (CPSC safety alert).
Here's what each one does, because the old version of this page got one of them wrong.
- Tip-over switch. It cuts the power if the heater falls over. It doesn't stop the heater falling, which is what the earlier version of this article said. A stable base and a sensible spot do that job. The switch is there for the day a child or a dog knocks it anyway.
- Overheat cut-out. It shuts the heater down if its own temperature climbs too high, usually because something's covering it or blocking the air around it.
- ISI mark. The Bureau of Indian Standards certifies room heaters against IS 302 (Part 2/Sec 30), the Indian safety standard for this type of appliance (BIS product manual). The CPSC's buying advice is simply to ask the salesperson whether the heater is safety certified and look for the mark. Ask us. We'll show you where it's printed.
How to use a heater safely once it's home, including whether to sleep with one on, is in the guide we linked near the top of this page. The short version from the CPSC is to keep beds, curtains and clothes 3 feet clear and never leave it running while you sleep.
Does a room heater need a 16 amp socket?
Any of the big radiators does, and you should check before the heater arrives, not after. A 2,900 W heater draws about 12.6 amps at 230 volts, and the listings for big radiators in our range, such as the Bajaj Vienna and the Glen HA7013DOR, specify a 16 amp socket.
The sum is watts divided by volts. A 2,400 W radiator pulls about 10.4 amps. A 2,900 W one pulls about 12.6.
What we don't want anyone doing is forcing the issue with an adapter or a multi plug board. The CPSC's advice is plain: never power a heater from an extension cord or a power strip, make sure the plug fits tightly into the wall outlet, and if the plug, socket or faceplate gets hot, stop using it and get an electrician to look at it (CPSC). If the room you want to heat has no 16 amp point, a smaller heater on the socket you have is a better answer than a big one on a borrowed connection. Or get the point put in before the cold arrives.
Is a quiet room heater worth it for a bedroom?
Yes, and the way to find one is to look for no fan, because heater listings don't quote decibels. An oil-filled radiator on radiator mode and a halogen heater are both silent. A fan heater always hums, and so does a radiator while its PTC fan is running.
The older version of this page told you to compare decibel ratings. We went through every room heater listing in our range, and not one of them quotes a decibel figure, so that advice sent people looking for a number that isn't there. Ask whether there's a fan, and whether the fan can be switched off. That tells you what you need to know.
A practical aside we give light sleepers: the PTC fan on a radiator is for the first few minutes. Warm the room with it, switch it off, and let the oil carry the night in silence.
Which room heater should you buy for your room size?
Choose a room heater from the size of the room, not the price tag, and these five cover the rooms we're asked about most, from a small study to a big drawing room. Every one of them has a tip-over or anti-tilt switch, and we've given the price band each sits in rather than a number that'll be out of date by the time you read it.
Hindware Ignitio 800W Halogen Room Heater
For the small study or one person at a desk, 80 sq ft and under. Under Rs 1,500. It's 800 W of silent halogen heat with no fan and no moving parts, three heat settings, a tip-over switch, a stable oval base and an LED indicator so you can see across a dark room that it's on. It warms what it faces rather than the whole room, so point it at the chair. The listing doesn't mention a thermostat, so treat it as a heater you switch on and off yourself. We suggest it when somebody tells us the cold only bothers them at the desk from nine to six.
USHA OFR 3609 FS PTC Oil Filled Room Heater
For the standard 10 by 12 bedroom. Under Rs 9,000. Nine wave fins on a 2,000 W oil-filled element plus a 400 W PTC fan, so 2,400 W in all, which is double what the room needs on paper and plenty for a cold corner flat. It has an adjustable thermostat, overheat protection, a tip-over switch and the ISI mark, and at 7.2 kg it's light enough to move between rooms. Two years of USHA warranty. This is the one we steer people towards when they've come in asking for the biggest radiator we have and the room turns out to be an ordinary bedroom.
Morphy Richards Heat Wave 11F Oil Filled Room Heater
For the 12 by 14 master bedroom. Under Rs 9,000. Eleven fins, a 2,500 W oil-filled element and a 400 W PTC fan for 2,900 W combined, with a manual adjustable thermostat, tip-over, overheat and auto shut-off protection and a cool-touch housing. Two years of comprehensive warranty. Yes, this is the heater whose box says 150 sq ft. By the watts it'll do more than that, and we'd happily put it in a room of 170 or so with a thermostat to hold it back on mild nights.
Morphy Richards Heat Wave 13F Oil Filled Room Heater
For the 14 by 16 living room. Under Rs 12,000. Thirteen fins on the same 2,500 W plus 400 W PTC arrangement, three heat settings under a thermostat, overheat protection, a tip-over switch and a cool-touch exterior. It weighs about 16 kg, so the castor wheels earn their keep. One year of Morphy Richards warranty. Same watts as the 11F, so you're paying for steadier, longer lasting heat across a bigger room, not more output. The old version of this page linked to a 13 fin Morphy Richards page that no longer opens. This is the 13 fin Morphy Richards we'd point you to now.
Russell Hobbs ROR 15F Oil Filled Radiator
For the 16 by 18 drawing room, the biggest room one heater should be asked to warm. Under Rs 13,000. Up to 2,900 W, with a 2,500 W lower setting, fan-forced heating to bring the room up quickly and a variable thermostat to hold it. Anti-tilt and overheat protection and a fire-retardant front body. What sets it apart is a built-in humidifier with an air freshener, which suits a room heated all evening, since every heater lowers the relative humidity as it warms the air. Two years of comprehensive warranty. Bigger than about 290 sq ft and we'd rather sell you two smaller heaters for opposite ends of the room than one that's always flat out.
Where can you buy a room heater online in Delhi NCR?
You can buy any of these online from us with delivery across Delhi NCR, or come in and we'll size it with you on paper. The full range, from small halogens to the biggest radiators, is in our heaters collection, and our electric heater vs oil-filled heater guide covers the two most common types head to head.
Our advice before you spend anything, and it costs us nothing to give it. Do three things at home first. Measure the room and multiply the square feet by 10. Look at the socket where the heater will go and see whether it's the big 16 amp one. Decide how many hours a day someone will be in that room. Bring those three answers in, or type them into a message to us, and we can tell you in a couple of minutes which heater fits. Quite often it's a smaller and cheaper one than you came in for. That's the best way we know to choose a room heater, and it's the advice we've been giving across the counter since 1981.