How many downlights do I need? A room-by-room guide for Malaysian homes

For a typical Malaysian terrace house, plan one 9W LED downlight (around 900 lumens) per 1-1.5 square metres in living areas, 1 per 1 square metre in kitchens, and 1 per 2-3 square metres in bedrooms. The proper formula is: (target lux x room area in m²) ÷ lumens per fixture = number of downlights. The rest of this post shows you how to use it.

The target lux levels you should plan to

Lux is light intensity at the surface (one lux equals one lumen spread across one square metre). Industry recommendations for residential spaces in tropical climates:

Older Malaysian homes were often lit to 80-150 lux throughout with one or two fluorescent tubes per room. Modern downlight planning aims much higher in the rooms where you actually do things, and lower in rooms where you don't.

Lumens per fixture — what to assume

LEDs vary, but as a planning rule of thumb for residential downlights:

• 5W LED ≈ 450-500 lumens
• 7W LED ≈ 650-700 lumens
• 9W LED ≈ 850-900 lumens
• 12W LED ≈ 1,100-1,200 lumens
• 15W LED ≈ 1,400-1,500 lumens
• 18W LED ≈ 1,700-1,800 lumens

The 9W and 12W downlights are the workhorses of Malaysian renovations. Anything below 7W is typically only good for accent or step lighting.

The calculation, step by step

Number of fixtures = (target lux × area in m²) ÷ lumens per fixture

Then add a 10-20% buffer for fitting efficiency (downlights aren't 100% efficient — some light is lost in the housing) and for the way light falls off near walls.

Worked example 1 — Terrace living hall

A typical terrace ground floor living hall: 4.5m × 4m = 18 m². Target ambient: 200 lux. Using 9W downlights (900 lumens each):

(200 × 18) ÷ 900 = 4 downlights

Add 20% buffer for efficiency: 4 × 1.2 = 4.8 → round to 5 downlights

Real-world fitting: a clean 3-column × 2-row grid would give you 6 downlights, which lets you dim down to your 5-equivalent target while having symmetry. Most renovators end up at 6-8 downlights in this size of hall because they want headroom and even spacing.

Add a feature pendant or floor lamp for warmth and you've got proper layered lighting.

Worked example 2 — Master bedroom

Master bedroom: 4m × 3.5m = 14 m². Target ambient: 150 lux. Using 9W (900 lm):

(150 × 14) ÷ 900 = 2.3 downlights

With 20% buffer: 2.3 × 1.2 = 2.8 → round to 3 downlights

Or 4 downlights in a 2 × 2 grid for symmetry, dimmable to taste, plus a bedside reading light and a wardrobe task light. You almost never want a bedroom blazing — keep it dimmable.

Worked example 3 — Kitchen

Galley kitchen: 3m × 2.5m = 7.5 m². Target ambient: 400 lux. Using 12W (1,200 lm):

(400 × 7.5) ÷ 1,200 = 2.5 downlights

With 20% buffer: 3 downlights minimum.

But kitchens also need task lighting over the prep counter and stove — typically under-cabinet LED strip (around 6-8W per metre) or pendants over the island. The 3 downlights handle ambient; the task layer makes it usable.

Worked example 4 — Dining

A 3m × 3m dining area = 9 m². Target ambient: 200 lux. Using 9W:

(200 × 9) ÷ 900 = 2 downlights

Add 20% buffer = 2.4 → round to 3, or 4 in a symmetric 2 × 2 around a central feature pendant. The pendant is doing the heavy lifting for the table itself; the downlights wash the surroundings. A statement chandelier over the table changes the whole feel of the room.

Spacing rule of thumb

Once you've got the count, spacing matters as much as quantity. The rule:

• Distance between downlights = 1 to 1.5 × ceiling height. For a 9 ft ceiling (≈ 2.7 m), that's 2.7-4 metres apart.
• Distance from wall = 1/2 × spacing. So roughly 1.3-2 metres from the wall.

This avoids the "spotlight on the floor" effect you get when downlights are crammed too close, and the dark corners you get when they're too far apart.

Wattage budget vs lumen budget

A common shortcut in Malaysian renovations is "use 1W per square foot" — which works out to about 11W per square metre. For a 200 lux target with reasonably efficient LEDs, that's actually a decent guideline and matches the formula above for most living spaces.

For higher-target rooms (kitchen, study), bump to 1.5W per square foot. For bedrooms, 0.7W per square foot is enough.

Common mistakes to avoid

• Forgetting the dimmer. Even a well-calculated count of downlights can feel too bright at night. Wire dimmers in living and bedroom from day one.
• All ambient, no task or accent. Downlights alone make a room feel flat. Layer in pendants, wall lights, lamps and cove lighting.
• One single colour temperature throughout. See our 3000K vs 4000K vs 6000K guide.
• Ignoring CRI. A high count of cheap CRI 70 downlights looks worse than a smaller count of CRI 90+ ones. See our CRI guide.
• Spacing only by aesthetics, not lighting.A pretty 4×4 grid in a 3m × 5m room will give you uneven coverage.

A calculator is here

We built an interactive lighting calculator so you can plug in your room size and target use, and get a recommended count, spacing diagram and shopping list. Try the lighting calculator — and our team can run the numbers for you over WhatsApp if you'd prefer.

Where to see it in person

Bring your floor plan (even a hand-drawn one with dimensions) to the showroom and we'll mark up downlight positions and recommend the right wattage and CRI per zone in about 15 minutes.

WhatsApp +60 11-5696 8200 with your room dimensions for a quick count and shopping list.