How Many Lumens Do I Need? A Room-by-Room Brightness Guide
How many lumens do I need is easily the question our team hears most often, and it is one that used to be far simpler to answer. For decades everybody shopped by wattage. A 60 watt bulb was a 60 watt bulb, and you knew exactly what you were getting when you brought one home. Then LED arrived, wattage stopped describing brightness, and the number that genuinely matters moved into the small print.
The good news is that lumens are easier to work with than watts ever were, once you know what to aim for. In this guide we explain what the figure on the box actually measures, share the simple sum we use to work out the brightness a room needs, and give target numbers for every space in the house, from a softly lit bedroom to a kitchen where you are chopping onions after dark.
Lumens, watts and lux explained
Lumens measure light. Watts measure electricity. That distinction did not matter much when almost every bulb was a filament, because output and consumption rose together in a predictable way. With LED, a fitting drawing 9 watts can easily out-perform an old 60 watt bulb, so wattage now tells you about your electricity bill and nothing whatsoever about how bright a room will feel.
Lux is the third term you will see, and it is simply lumens spread over an area, measured as lumens per square metre. It describes the light actually landing on a surface rather than the light leaving the bulb, which is why a kitchen worktop and a kitchen ceiling can have very different lux readings from the same fitting. Professionals design to lux, but for a home the lumen total is usually enough.
If you want a quick translation from the old system, roughly speaking a 40 watt bulb gave around 450 lumens, a 60 watt gave around 800, and a 100 watt gave around 1,500. Every bulb sold in the UK carries its lumen figure on the packaging, and all of our light bulbs list it clearly on the product page so you can match what you had before without any guesswork.
The simple sum for working out any room
Start by measuring the room in square metres, multiplying its length by its width. Then multiply that figure by the lumens per square metre the room needs. As a working rule our team uses 150 lumens per square metre for relaxed spaces such as living rooms and bedrooms, and 250 to 300 for rooms where you are concentrating, cooking or grooming.
A worked example makes it obvious. A living room measuring 4 metres by 5 metres comes to 20 square metres, and at 150 lumens per square metre that gives a target of about 3,000 lumens for the whole room. A galley kitchen of 8 square metres needs roughly 2,400 lumens at the higher rate, even though it is a far smaller space.
Then adjust for the room itself. Dark walls, deep colours and heavy furniture swallow light, so add around 20 per cent if your scheme is on the moody side. High ceilings mean the light has further to travel before it reaches you, which is worth another 10 to 20 per cent. Pale walls and a north-facing aspect pull in opposite directions, so trust your eyes as well as the sum.
Living rooms and bedrooms: comfortable rather than bright
Living rooms sit at the gentler end of the scale, typically wanting somewhere between 3,000 and 6,000 lumens in total depending on size. That sounds like a great deal until you remember it is a total across every fitting in the room, not a single bulb. A sitting room lit to that level from four or five sources feels warm and settled, while the same figure from one central pendant feels like a waiting room.
Bedrooms need less again, usually 1,500 to 3,000 lumens, because the room's main job in the evening is to help you wind down. Keep the overhead light modest and put the effort into bedside lamps of around 400 to 500 lumens each, which is comfortable for reading without waking anybody who has already turned in. A dimmer on the main fitting earns its keep here more than anywhere else in the house.
Both rooms benefit enormously from having several smaller sources rather than one powerful one. Our living room lighting range is built around exactly that idea, mixing ceiling fittings with table lamps, floor lamps and wall lights so you can bring the level up for a family afternoon and drop it right down for a film in the evening.
Kitchens, bathrooms and desks: where you need more
Kitchens are the brightest rooms in most homes and should be, given that knives, hobs and hot pans are involved. Aim for 4,000 to 8,000 lumens in total for a family kitchen, and make sure a decent share of it lands on the worktop rather than the floor. Under-cabinet strips are the single best upgrade most kitchens can have, because they put light exactly where your hands are working.
Bathrooms want good, even light around the mirror above all else. A general level of around 400 lux across the room is the professional target, which for a typical 6 square metre bathroom works out at roughly 2,400 lumens. Light from both sides of the mirror at face height beats a single bright downlight overhead every time, since it fills in the shadows instead of casting them.
Desks and worktops are judged on the task rather than the room. Around 500 lux on the working surface is the standard for detailed work, which usually means a dedicated task lamp of 400 to 800 lumens close to the job in hand rather than a brighter ceiling fitting. Our kitchen lighting collection includes plenty of fittings designed to sit low over an island where that focused light is most useful.
Hallways, stairs and landings: the spaces everyone under-lights
Hallways are consistently the dimmest rooms in British homes, usually because they were fitted with one small pendant and never revisited. A hall wants 800 to 1,500 lumens, and the number matters less than the evenness. A single bright source at one end leaves the far end in gloom, which is exactly the impression a visitor takes away when they step through your front door.
Stairs deserve particular care because the consequences of poor light are practical rather than aesthetic. You need enough brightness to read the edge of every tread clearly, with no glaring source shining into the eyes of somebody coming down. Wall lights running up alongside the staircase handle this far better than one fitting at the top, and they look considerably more intentional.
Landings sit between the two and are often the easiest win in the house. A modest ceiling fitting of around 800 lumens, plus a small lamp on a console or a chest of drawers, turns a functional corridor into somewhere that feels like part of the home. It also means nobody has to flood the whole floor with light on the way to the bathroom at two in the morning.
Splitting the total across layers
Reaching your lumen target from a single fitting is the most common mistake we see. One very bright bulb in the middle of the ceiling produces flat, shadowless light with dark corners around the edges, which is why so many rooms feel harsh in the evening despite being technically bright enough on paper. The total is only half the story, and where the light comes from is the other half.
The split our team works to is roughly 40 to 50 per cent of the total from the ceiling and the remaining 50 to 60 per cent from lamps, wall lights and anything else at lower level. For that 3,000 lumen living room, that means around 1,400 lumens overhead and the rest spread between a pair of table lamps, a floor lamp beside the reading chair and perhaps a wall light or two.
This is also what makes a room adaptable. With the light split across several sources you can run the whole set for a bright afternoon, then switch off the ceiling fitting entirely and keep only the lamps for the evening, without ever ending up in the dark. Our table and floor lamps are the workhorses of that approach, and most rooms want at least two.
Brightness, colour and control working together
Lumens tell you how much light you are getting, not what it feels like. Colour temperature is the companion number, measured in kelvin, and for living rooms and bedrooms our team recommends 2,700K warm white. Kitchens, bathrooms and home offices can take 3,000K to 4,000K, which reads as crisper and cleaner without tipping into the cold blue tone nobody wants at home.
Dimming is what makes a generous lumen figure genuinely liveable. Specify slightly more brightness than you think you need, then fit dimmable bulbs and a compatible dimmer switch so you can take it down when you want to. Check that both the bulb and the switch are marked as LED compatible, because an older dimmer paired with a modern LED is the usual culprit behind flickering and buzzing.
If you take one thing from this guide, let it be that the target figure is a starting point rather than a rule. Measure the room, do the sum, split the total across three or four sources, then live with it for a week and adjust. Our team is always happy to talk brightness through before you order, whether you are lighting one room or planning a whole house.
Frequently asked questions
How many lumens do I need for a living room?
A living room usually needs between 3,000 and 6,000 lumens in total, depending on its size. Work it out by multiplying the floor area in square metres by around 150 lumens. That total should come from several fittings rather than one, ideally about 40 to 50 per cent from the ceiling and the rest from table lamps, floor lamps and wall lights.
How many lumens is a 60 watt bulb?
An old 60 watt filament bulb produced roughly 800 lumens. For comparison, a 40 watt gave around 450 lumens and a 100 watt around 1,500. An LED bulb reaching 800 lumens typically draws only 8 to 10 watts, which is why wattage is no longer a useful guide to brightness and the lumen figure on the packaging is the one to check.
How do you calculate how many lumens a room needs?
Multiply the room's length by its width to get the floor area in square metres, then multiply by the lumens per square metre for that type of room. Use around 150 for relaxed spaces such as living rooms and bedrooms, and 250 to 300 for kitchens, bathrooms and workspaces. Add about 20 per cent for dark walls or a high ceiling.
How many lumens should a kitchen have?
A family kitchen generally needs 4,000 to 8,000 lumens in total, making it the brightest room in most homes. Just as important is where that light lands, so include under-cabinet lighting or low-hung pendants over an island to put light directly onto the worktop rather than relying on a ceiling fitting behind you.
Is more lumens always better?
No. Too much light feels clinical and uncomfortable, particularly in the evening, and a very bright single fitting creates glare and hard shadows. A moderate total spread across three or four sources at different heights will always feel better than one powerful bulb. Fitting a dimmer gives you the flexibility to use the full output only when you need it.
