How many lumens do I need?

Below is a quick equation to help you figure out how many lumens you may need to illuminate your room.

What are lumens?

Lumens are the unit used to measure a bulb’s brightness, whether it’s LED, halogen, fluorescent etc. In the past we relied on wattage to tell us this.

However, as LED lights became more commonplace, wattage was no longer suitable as a measurement. It doesn’t indicate how bright the light will be—instead, it’s a measure of how much electricity a bulb consumes.

LEDs have become popular because they provide brightness for less wattage. For example, a 5w LED will produce the same lumens as a 40w CFL bulb.

When looking for LED brightness, consider the lumens, not the wattage.

The equation

Room square footage X room type (foot candle recommendation)

Calculating how much light you need per room requires two figures:

  1. Number of foot candles needed
  2. The square footage of the room

What are foot candles?

Each room of your house needs different levels of brightness and a different number of foot candles. The table below shows the recommended number of foot candles per room:


Recommended number of foot candles

Living room




Dining room








NOTE: These foot candle recommendations are for general use. They don’t account for areas that need more light, such as dining-room tables, cookers etc.

If your room has dark walls or furniture, you’ll need lighting with more lumens.

How to measure the square footage of a room

Square footage is a standard way to measure a room. To figure out a room’s square footage, multiply the length of the room by its width.

For example, if a room is 10 foot long and 10 foot wide, the room’s square footage will be 100 square feet.

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