How many lights does a room need?

Multiply the room area in square metres by the recommended lux for that room to get total lumens, then divide by the lumens of each fixture. For example, a 14 m² living room at 150 lux needs about 2,100 lumens, or three 800-lumen lights.

What lux level do rooms need?

Roughly 100–150 lux for living rooms and bedrooms, 300 for kitchens and study or work areas, and 150 for bathrooms. Task areas need more focused light.

How many lumens is an LED bulb?

A 9–10 watt LED gives about 800–900 lumens. LEDs produce roughly 90–100 lumens per watt, so wattage is total lumens divided by about 90.

Lighting Calculator (India)

Lighting Calculator

Work out how many lights a room needs. Pick the room type for its recommended brightness, enter the area and the lumens per fixture, and you'll get the number of lights, total lumens and an estimated wattage.

Room & light

Room type 150 lux

Enter area as

Measured in

Length ft

Width ft

Lumens per light e.g. 800 = 9W LED

How it's calculated

Total lumens are the floor area in square metres times the recommended lux for the room. Dividing by the lumens of each fixture, rounded up, gives the number of lights. Wattage assumes efficient LEDs at about 90 lumens per watt. This is general ambient lighting — task and accent lights are extra.

Lights = ⌈(area m² × lux) ÷ lumens per light⌉. Watts ≈ total lumens ÷ 90.

Frequently asked questions

Does this cover task lighting?

No — it sizes general ambient light. Add focused lights over counters, desks and mirrors.

Higher ceilings?

Tall rooms lose light at the floor; add 10–20% more for ceilings above ~3 m.

Warm or cool light?

Colour temperature doesn't change lumens needed; pick warm for living areas, cooler for kitchens and work.