How Many Downlights Do I Need? A Layout Guide for Singapore Rooms
Last updated: 8 October 2026
Quick answer: To find how many downlights you need, multiply the floor area in sqm by a target in lumens per sqm, then divide by the lumens each downlight gives. Using a non-official planning reference of 300β500 lm per sqm for living areas, an example 20 sqm living room (4 m by 5 m) needs about 6,000 to 10,000 lumens, which is four to six Philips LED Recessed Downlight 15W (Round) units at about 1600 lm each, per the listing. Spacing then settles the number: in that example room, six in two rows of three, about 1.7 m to 2 m apart, give even cover.
Step 1: Work out the lumens your room needs
Total lumens needed = floor area (sqm) Γ target lumens per sqm.
Target levels differ between sources and depend on how the room is used, so treat any figure as a planning assumption. This guide uses 300β500 lm per sqm installed for living and common areas and 400β600 lm per sqm for kitchens and study areas, the same non-official planning reference we use in our HDB lighting guide.
Here is the sum for a 20 sqm living room, for example 4 m by 5 m (an example size, so measure your own): 20 sqm Γ 300 to 500 lm per sqm = 6,000 to 10,000 lumens. Divide by the lumens on each listing to see how many lights keep the total in that range:
| Downlight | Lumens per light (listing) | Lights for 6,000β10,000 lm | Total |
|---|---|---|---|
| Philips LED Recessed Downlight 15W (Round) | about 1600 lm | 4 to 6 | about 6,400 to 9,600 lm |
| Dahlia Recessed Smart Downlight 12W Round 3-Tone | 1080 lm | 6 to 9 | 6,480 to 9,720 lm |
These are installed lumens, the total of the figures on the listings, not a measured light level at the floor; dark walls and floors absorb more light, so lean towards the upper end in those rooms. For a small space such as a corridor, a lower-output light such as the Philips LED Recessed Downlight 6W (Round) (about 600 lm, per the listing) may be enough. Our downlight range runs from 3W up to 24W, so you can choose the output per light to suit your layout.
Step 2: Check the spread, because the lumen count alone can leave dim patches
Four 15W downlights reach the low end of that range in the example room, but four lights in a 4 m by 5 m room would sit about 2 m by 2.5 m apart, so check spacing as well. These are common rules of thumb, not rules, and they are starting points for your own room:
- Between lights: about 1.5 m to 2 m is a common starting point. Lights with a wider beam angle can sit further apart; narrow beams need to be closer.
- From the wall: about half the spacing between lights, so the room edge is not left dim.
- To wash a wall (curtains, art or a feature wall): bring that row closer to the wall than the edge gap above. Ordinary downlights can leave a pattern of bright arcs on the wall.
Use the two checks for different jobs: the lumen range decides how many lights of a given output you need, and the spacing rules decide where they go. In the example room, the 15W option allows four to six lights. Four would leave gaps of about 2 m by 2.5 m, wider than that starting point, and five do not make an even grid, so plan six in two rows of three: about 9,600 lm in total, gaps of about 1.7 m to 2 m, and about 0.8 m to 1 m from the walls. If no number in the lumen range gives even gaps, keep the lumen total and change the output per light. So for this example room, plan six Philips 15W downlights.
| Approach | What you gain | What it costs |
|---|---|---|
| Fewer, higher-output downlights | Fewer ceiling cut-outs and wiring points | Brighter pools of light, with more risk of dim patches between them and glare when you look up |
| More, lower-output downlights | Softer, more even light, and you can switch some off | More cut-outs, fittings and wiring |
Beam angle is how widely a light spreads: the Philips 15W lists 110Β° and the Dahlia 12W Round lists 120Β°, and a wider beam covers more floor from each position. If your plan sits near the upper end of the range, dimming lets you turn the level down; the Philips 15W listing says “Dimmable: No”, so check each listing before you plan.
Downlights do not have to light the room alone. If track lights, a cove strip or lamps carry other layers, you may need fewer downlights.
For how the three layers fit together, see our layered lighting guide.
Where to put downlights, and where not to
Place downlights to suit what people do in the room, not only to fill a grid. These are suggestions, not rules.
| Where | Suggestion | Why |
|---|---|---|
| Above a sofa seat or bed head | Move the light forward of or beside the seat or pillow line | Someone leaning back or lying down can look straight into the light, which causes glare |
| Along a wall of curtains, art or shelves | Bring a row closer to the wall, as in the wall-washing rule above | A lit wall can make a room feel brighter than the floor level alone suggests |
| Kitchen counter | Position lights above the front edge of the counter, not behind you | Your shadow then does not fall on the worktop |
| Art or a feature you want to highlight | Use an aimable spotlight or track light | A standard downlight points straight down; see our Spotlight range |
“Adjustable” in a downlight’s name can mean different things. The Lighting Hub Adjustable Downlight 15W (Round) listing says “Adjustable from 50β210 mm”, which is the opening size, and does not state a tilt angle. Check the cut-out size on the listing before you mark positions; the Philips 15W lists about 175 mm.
For how to measure the hole before you buy a replacement, see our downlight cut-out size guide.
Adding or moving lighting points is wiring work, so agree the positions with your electrician before the ceiling is closed.
Keep one colour temperature in each room
Use the same colour temperature for all the downlights in a room so the pools of light match. The usual options are 3000K Warm White, 4000K Cool White and 6500K Daylight; the Philips 15W lists all three Kelvin values, and the label wording varies between listings, so go by the number.
For what each colour temperature looks like and which room suits which, see our colour temperature guide.
Send us your floor plan
Not sure how many downlights each room needs? Send your floor plan to our light specialist, who can assess it and recommend how many fittings each space needs. Our lighting design service page shows how to book. You can also see downlights in person at one of our 5 showrooms; call the branch first to check what is on display.
If you would like the downlights installed as well, send an installation enquiry with your ceiling type and ceiling height.
FAQ
How many downlights do I need for a living room?
Multiply the floor area in sqm by a target in lumens per sqm, then divide by the lumens each downlight gives. Using a non-official planning reference of 300β500 lm per sqm for living areas, an example 20 sqm living room needs about 6,000 to 10,000 lumens, which is four to six Philips LED Recessed Downlight 15W units (about 1600 lm each). In an example 4 m by 5 m room, six in two rows of three, about 1.7 m to 2 m apart, give an even layout.
How far apart should downlights be?
A common starting point is about 1.5 m to 2 m between lights, with the outer lights about half that distance from the wall. It is a starting point, not a rule: lights with a wider beam angle can sit further apart, and narrow beams need to be closer.
How far should a downlight be from the wall?
As a rule of thumb, about half the spacing between lights for general lighting, so the room edge is not left dim. To light a wall such as curtains or a feature wall, bring the lights closer to it than that. These are starting points, so send us your floor plan to check your layout.
Is it better to use more small downlights or fewer big ones?
It depends on the room. More, lower-output downlights give softer, more even light and let you switch some off, but need more cut-outs and wiring. Fewer, higher-output ones need less ceiling work but can leave dim patches or glare. Work out the lumen range first, then choose the number and output that keep the total in that range with even gaps.
Where should I avoid placing downlights?
Try not to put a downlight directly above where people sit or lie looking up, such as a sofa seat or bed head, because the bare light source can cause glare. In a kitchen, place lights above the front edge of the counter rather than behind you, so your shadow does not fall on the worktop. These are layout suggestions, not rules.
Written by the Lighting Hub team, Since 2009.
