The conversion between lumens and watts is important if you want to replace your old light sources with modern LED lamps. In case of LED lamps and luminaires, the specified wattage plays only a subordinate role. Much more important is the actual brightness, which is given in lumen. Here you will find all necessary information to calculate the needed lumens for your preferred brightness.
Contents
Conversion between Lumens and Watts
This article explains the difference between lumens and watts and why the lumen value is an important specification for modern LED lights. You can get a quick overview on the Lumen Watt Comparison Table. The article also offers an online calculator with two main functions:
- Convert lumens to watts
- Convert watts to lumens
Convert lumens to watts
Old light sources such as incandescent bulbs or halogen lamps were easy to choose. Here the wattage was the most important indicator for the brightness. If a 60W bulb fails, it could be simply replaced by a new 60W bulb. The replaced lamp was just as bright as before and there was no need to worry about the correct brightness.
For LED lamps, the power consumption is also indicated in watts. But the wattage plays a minor role now and only allows a very rough conclusion on the actual brightness. Different components in various LED lamps lead to varying brightness with the same power consumption.
For example, a 5W LED illuminant of type A can light up much brighter than another 5W LED lamp of type B. This is possible because lamp A could have a better efficiency due to high quality components and therefore emits more light. For the comparability of LED lamps the actual brightness is indicated in lumens.
What are lumens?
The unit lumen describes the luminous flux emitted by a light source. This is the power emitted per second in the wave range of visible light. For LED luminaires and illuminants, this must always be stated in the product description. The lumen specification is often given in the short form lm.
You can use the lumen value to compare the brightness of different lamps, regardless of their efficiency and lighting technology. The brightness in lumens is super important when using LED lamps. The Lumens to Watts Calculator helps you to compare the brightness of different light sources.
Lumens to Watts Converter
This free online calculator will help you convert lumens to watts and vice versa. So you can calculate how many lumens the new LED lamps should have based on your previous lights. If you already have some LED lamps on your shortlist, you can convert their lumen value into the output (in watts) of previous lighting.
Calculator help
Lumens to watts conversion
Example 1: You see an offer for an LED torchiere. The light output is 1800 lumens and you want to know how bright it is compared to an old halogen torchiere.
In the calculator you have to select Lumens to Watts as conversion type, enter the value 1800 and select the item Halogen lamp as comparison type. After a click on the calculate button you will see the wattage of an equally bright halogen torchiere.
Convert watts to lumens
Example 2: You have a torchiere with two 35W bulbs and want to replace them with LED lights.
In the calculator, select Watts to Lumens as the conversion type, enter the value 35 and select the item Light bulb for comparison. After a click on the calculate button the luminous flux is displayed in lumens. The result should serve as a guideline for the brightness of the new LED lights.
Lumens to Watts Comparison Table
In this table you will find a comparison of the power consumption and the respective brightness of all common light sources. The values are average values of the respective lighting technology and vary by manufacturer.
| Lumens | Light bulb | Halogen lamp | Energy-saving lamp | LED | |
|---|---|---|---|---|---|
| 230 – 270 lm | 25 watts | 19 watts | 6 watts | 2 – 3 watts | Buy Now |
| 430 – 450 lm | 40 watts | 35 watts | 9 watts | 4 – 6 watts | Buy Now |
| 730 – 800 lm | 60 watts | 50 watts | 13 watts | 7 – 9 watts | Buy Now |
| 970 – 1100 lm | 75 watts | 64 watts | 19 watts | 8 – 11 watts | Buy Now |
| 1380 – 1600 lm | 100 watts | 84 watts | 23 watts | 12 – 14 watts | Buy Now |
| 1500 – 1800 lm | 120 watts | 98 watts | 32 watts | 15 – 17 watts | Buy Now |
| 2000 – 2500 lm | 150 watts | 122 watts | 40 watts | 18 – 23 watts | Buy Now |
Example Comparisons
LED Equivalent for 60 Watt Bulb
You will find the 60 watt bulb in the 3rd row of the 2nd column. It has a brightness of about 730 lumens. You will find the suitable LED replacement in the 5th column of the same row. With the same brightness, the LED only needs 7 to 9 watts, depending on manufacturer and model.
LED Equivalent for 13 Watt CFL Bulb
You can find the 13 watt CFL bulb in the 3rd row of the 4th column. It has a brightness of about 800 lumens. You will find the suitable LED replacement in the 5th column of the same row. With the same brightness, the LED only needs 7 to 9 watts, depending on manufacturer and model.
Watts to Lumens Comparison
This table shows an inverted comparison of the power consumption and the respective brightness of all common light sources. The values are average values of the respective lighting technology and vary by manufacturer.
| Power | Light bulb | Halogen lamp | Energy-saving lamp | LED |
|---|---|---|---|---|
| 5 W | – | – | 180 lm | 500 lm |
| 7 W | – | – | 290 lm | 700 lm |
| 9 W | – | – | 400 lm | 850 lm |
| 11 W | – | – | 530 lm | 1200 lm |
| 14 W | – | – | 730 lm | 1500 lm |
| 25 W | 230 lm | 300 lm | – | – |
| 40 W | 430 lm | 500 lm | – | – |
| 60 W | 730 lm | 900 lm | – | – |
| 75 W | 970 lm | 1200 lm | – | – |
| 100 W | 1380 lm | 1700 lm | – | – |
The brightness specifications for LED technology varies greatly depending on the quality of the light sources. Due to the active development of LED technology, a further increase in lumens per watt can be expected in the coming years.
Important notes for lumens to watts conversion
The luminous flux or brightness in lumens only indicates the intensity. The direction or beam angle of the emitted light is not taken into account. So the lumen value says nothing about how the light is diffused in the room. Old light bulbs and halogen lamps emit their light almost all around. Many LED lamps, on the other hand, have a lower beam angle.
For this reason, the lumen value of an LED lamp can often be slightly lower than with the old light source. With a luminaire above the dining table for example, the table would be illuminated just as brightly as before, only the indirect lighting of the ceiling would be darker than before.
Conclusion
Before you replace old light sources with modern LED lamps, you should think about the desired brightness. This avoids disappointments that the new LED lamp is much darker than the old incandescent lights.
To find LED lamps with the correct brightness, you should use the lumen value of the old lighting as a starting point. The online calculator above and the comparison table will help you to choose the right LEDs.
