# Lumens to watts

Obtain the equivalence between lumens and watts is possible thanks to our online calculator. You simply have to specify the luminous intensity in lumens as well as its efficiency in lumens/watt. If you do not know the latter, you can select the type of light source you are going to use to know, approximately, its efficiency.

When you have all the data, click on the calculate button and you will get the power in watts that consumes that bulb that you are going to use.

## How to convert from lumens to watts

If you want to know how to convert from lumens to watts, there is a formula that relates the luminous flux in lumens to the efficacy of the light source. The formula is as follows:

P(W) = ΦV(lm) / η(lm/W)

• ΦV(lm)is the luminous flux expressed in lumens or lm
• η(lm/W)The luminous efficacy or luminous efficiency index of the source is expressed in lumens per watt (lm/w).

After performing the operation, the value obtained is the power in watts.

## LED vs Incandescent Comparison

The efficiency index is what determines the energy savings, and therefore LED bulbs are more energy efficient than halogen bulbs. or the incandescent bulbs that are no longer manufactured.

Below you have a comparative table in which you can see how at equal lumens, an incandescent bulb consumes significantly more power than the LED equivalent:

LumensIncandescent bulb wattage (W)Fluorescent / LED (W)
375 lm25 W6,23 W
600 lm40 W10 W
900 lm60 W15 W
1125 lm75 W18,75 W
1500 lm100 W25 W
2250 lm150 W37,5 W
3000 lm200 W50 W

If you want to know the savings in electricity you would have each month by taking the leap to efficient lighting, here is a link to a LED savings calculator that will let you know how long it will take you to amortize the purchase of all the light bulbs in your home.