Room Lighting Calculator: Lumens and LED Bulbs for Your Room
Free tool · Updated October 2, 2026 · By CouponTalk
Your result
Enter your measurements to see your result.
Quick answer
Lumens needed = room area in square metres × the light level the room needs, in lux. A 12 × 10 ft (11.1 m²) living room at 150 lux needs about 1,700 lumens, which is two 9 W LED bulbs (900 lumens each) or one 20 W LED batten. A kitchen or study needs two to three times that. Modern LEDs give about 100 lumens per watt.
How to use this calculator
- Measure the room's length and width in feet.
- Pick the room type; each needs a different light level.
- Split the lumens across ceiling lights, and add a task light for desks and kitchen counters.
Lighting levels by room
| Room | Light level | Lumens per 100 sq ft | LED bulbs per 100 sq ft |
|---|---|---|---|
| Bedroom | 100 lux | 929 lm | 2 × 9 W bulbs |
| Living room | 150 lux | 1,394 lm | 2 × 9 W bulbs |
| Bathroom | 150 lux | 1,394 lm | 2 × 9 W bulbs |
| Dining | 200 lux | 1,858 lm | 3 × 9 W bulbs |
| Kitchen | 300 lux | 2,787 lm | 4 × 9 W bulbs |
| Study / desk | 400 lux | 3,716 lm | 5 × 9 W bulbs |
These are typical figures for Indian homes. Check the product spec sheet, and ask an electrician or installer before you buy or fit anything.
Frequently asked questions
How many lumens is a 9 W LED bulb?
About 800–950 lumens, depending on the brand. The lumen figure is printed on the box.
Should I choose warm white or cool daylight?
Warm white (2,700–3,000 K) suits bedrooms and living rooms. Cool daylight (5,700–6,500 K) suits kitchens, studies and bathrooms.
Does a dark wall colour need more light?
Yes. Dark walls absorb light, so add about 20–30% more lumens.
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