How Many Lumens Do I Need? LED Lumens vs Watts in Singapore
Last updated: 8 October 2026
Quick answer: Lumens (lm) measure how bright a light is, and watts (W) measure how much electricity it uses. To find how many lumens a room needs, multiply its floor area in sqm by a target in lumens per sqm; divide that total by the lumens stated on each product listing to get the number of fittings. Targets vary between guides; our non-official planning references are about 300 to 500 lm per sqm for living areas and 400 to 600 lm per sqm for kitchens and study areas.
Lumens measure brightness, watts measure power use
Lumens tell you how much light a bulb gives out. Watts tell you how much power it draws. With older bulbs the watt rating was a fair guide to brightness, but an LED makes more light from each watt, so a low-watt LED can match the brightness of a much higher-watt older bulb. That is why lumens are the figure to compare when you choose a bulb.
Lumens per watt (lm/W), also called efficacy, shows how much light you get for each watt of power. Divide the lumens by the watts to work it out. The Philips Essential LED Bulb 5W (50W) MR16 24D lists “Luminous Flux: 400 lm” and “Efficiency: 80 lm/W”, and 400 Γ· 5 = 80. For the same lumens, a higher lm/W means lower power use.
LED equivalent wattage: what our listings say
An equivalent wattage is the maker’s claim that an LED gives about the same light as an older bulb of that wattage. Some of our Philips listings state one next to the lumens, in slightly different wording:
| Product on our site | LED watts | Lumens on the listing | Equivalent on the listing | Lumens per watt (lumens Γ· watts) |
|---|---|---|---|---|
| Philips Essential LED Bulb 5W (50W) MR16 24D | 5W | 400 lm | “Wattage Equivalent: 50W” (listed as a halogen replacement) | 80 |
| Philips SceneSwitch LED A60 Bulb E27 8W (70W) | 8W | 880 lm | “Wattage Equivalent: 70W” | 110 |
| Philips LED Bright E27 Bulb, 13W option | 13W | 1,500 lm | “13W (99W Replacement)” | about 115 |
| Philips LED Bright E27 Bulb, 15W option | 15W | 1,800 lm | “15W (115W Replacement)” | 120 |
| Philips LED Bright E27 Bulb, 17W option | 17W | 2,250 lm | “17W (140W Replacement)” | about 132 |
These are the figures as stated on each listing, and the link between lumens and the equivalent is not the same on every listing: 880 lm is listed against 70W, while 1,800 lm is listed against 115W. As a commonly quoted rule of thumb, a 60W incandescent bulb is put at roughly 800 lm. Whichever figure you start from, compare lumens first and treat the equivalent as a hint.
How many lumens does a room need?
Multiply the floor area by a target in lumens per sqm, then divide by the lumens per fitting. In four steps:
- Measure the room’s length and width in metres and multiply them to get the floor area in sqm.
- Pick a target in lumens per sqm for how you use the room, from the table below.
- Multiply the area by the target to get the total lumens for the room, counting all its lights together.
- Divide the total by the lumens on each listing and round up to whole fittings.
These are the non-official planning references that our HDB lighting ideas guide also uses, and other guides give different figures, so treat them as a starting point:
| Space | Planning reference |
|---|---|
| Living and common areas | about 300 to 500 lm per sqm |
| Kitchens and study areas | about 400 to 600 lm per sqm |
They are planning references, not regulations.
Worked example: a 10 sqm room planned at 400 lm per sqm needs about 4,000 lm in total (10 Γ 400). Dividing by the lumens on each listing and rounding up gives:
| Fitting | Lumens on the listing | Number needed for about 4,000 lm | Total lumens |
|---|---|---|---|
| Philips LED Recessed Downlight 15W (Round) | ~1600 lm | 3 | ~4,800 lm |
| Philips LED Bright E27 Bulb 13W | 1,500 lm | 3 | 4,500 lm |
| Philips LED Bright E27 Bulb 17W | 2,250 lm | 2 | 4,500 lm |
Rounding up can overshoot a little, and the Philips listings used in this guide all state Dimmable: No, so look for a dimmable product if you want to turn the light down. These totals also ignore light lost inside fittings and shades, so treat the answer as a starting point.
For how many downlights a room needs and where to place them, see our downlight layout guide.
What changes how many lumens a room needs
The planning references are a starting point, and a few things move the answer:
- Ceiling height. The higher the ceiling, the further the light travels before it reaches the floor, so a tall room usually needs more lumens than a low one of the same floor area.
- Wall and ceiling colour. Dark finishes absorb more light than pale ones, so a room with dark walls usually needs more lumens for the same effect.
- What you do there. Cooking, reading and studying need more light than relaxing, which is why the kitchen and study reference above is higher than the living one.
Colour temperature is not a measure of brightness: it sets whether the light looks warm or cool, such as 3000K Warm White, 4000K Cool White or 6500K Daylight. Compare brightness by the lumens on the listing.
To choose between these colour temperatures for each room, see our colour temperature guide.
LED, CFL, halogen and incandescent compared
For the same light, an LED uses less power and has a longer rated life than the older types in the table. You can browse LED options in our light bulbs category.
| Type | How it makes light | Commonly quoted rated life | Heat and efficiency |
|---|---|---|---|
| Incandescent | Heats a thin filament until it glows | About 1,000 hours | Most of the power becomes heat; the fewest lumens per watt of the four |
| Halogen | An incandescent filament inside halogen gas | About 2,000 hours | Also runs hot; fewer lumens per watt than CFL or LED |
| CFL (compact fluorescent) | A folded fluorescent tube | About 8,000 hours | Cooler than incandescent or halogen; fewer lumens per watt than LED |
| LED | LED chips powered by a driver | Up to 15,000 hours on the bulb listings above; up to 20,000β30,000 hours on the 15W downlight listing | Runs cooler; 80 to about 132 lm/W on the bulb listings above |
Rated life is the maker’s rating, not a guarantee, and the hours for incandescent, halogen and CFL are commonly quoted figures that vary by product.
Recycling old bulbs in Singapore
NEA’s Where to Recycle E-waste page (last updated 28 September 2026, checked 8 October 2026) lists where used bulbs and lamps can go. It states:
- For the 3-in-1 bin (ICT, Batteries and Lamps): “Light bulbs with bulb circumference of no more than 100mm.”
- For the Battery and Bulb bin: “Bulbs and lamps are accepted.”
- On tubes: “Long fluorescent/LED tubes are not accepted.” and “Please dispose them through ALBA’s collection drives or doorstep collection.”
Check the page for your nearest bin and the current rules.
Before you buy
Read four things on the listing: the lumens (labelled Luminous Flux or Lumen on many of our pages), the colour temperature, whether it is dimmable, and the base type, which must match your holder. Compare more fittings in our downlights category.
To check which base your bulb or holder uses, see our guide to light bulb base types.
Send us your floor plan
If you are planning a whole flat or a renovation, send your floor plan to our light specialist, who can assess your drawings and suggest fittings and quantities. Our lighting design service page explains how to get in touch. You can see many of our bulbs and fittings at our 5 showrooms; call the branch first if you want to check a specific model.
FAQ
How many lumens do I need for a room?
Multiply the room’s floor area in sqm by a target in lumens per sqm to get the total lumens the room needs, then divide that total by the lumens on each listing to get the number of fittings. Targets vary between guides; our non-official planning references are about 300 to 500 lm per sqm for living areas and 400 to 600 lm per sqm for kitchens and study areas.
What is the difference between lumens and watts?
Lumens (lm) measure how bright a light is. Watts (W) measure how much electricity it uses. Because LEDs make more light per watt than older bulbs, watts no longer tell you how bright an LED is, so compare lumens when you choose a bulb.
What does lm/W mean on a light bulb listing?
Lumens per watt (lm/W) is efficacy, the amount of light you get for each watt of power. Divide the lumens by the watts to work it out: our Philips Essential LED Bulb 5W (50W) MR16 24D lists 400 lm and an efficiency of 80 lm/W. For the same lumens, a higher lm/W means lower power use.
How many watts is an LED bulb equal to?
There is no single conversion, because an equivalent is the maker’s claim and varies by listing, so compare lumens first. For example, our Philips SceneSwitch 8W bulb is listed at 880 lm against 70W, and our Philips LED Bright E27 15W bulb at 1,800 lm against 115W.
Where can I recycle old light bulbs in Singapore?
NEA’s Where to Recycle E-waste page lists the options. It names the 3-in-1 bin (with a bulb size limit) and the Battery and Bulb bin for bulbs, and says long fluorescent/LED tubes are not accepted in the bins. Check the page for the nearest bin and current rules.
