How to Convert Lumens to Watts?

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Lumens and watts are two important measurements when it comes to choosing the right led lighting bulbs. In the past, people relied on wattage to determine the brightness of a bulb. However, with the introduction of energy-efficient lighting options like LEDs and CFLs, lumens have become the standard unit of measurement for brightness. In this article, we will explore the difference between lumens and watts, how to convert lumens to watts, and why it is important to consider both when selecting led lighting bulbs.

What are Lumens?


Lumens are a measure of the total amount of visible light emitted by a light source. In simple terms, it indicates the brightness of a light bulb. The higher the number of lumens, the brighter the light. Lumens are indicated by the unit “lm” and are a more accurate measure of brightness compared to wattage. When shopping for lighting bulbs, you will often find the lumen rating clearly displayed on the packaging.

What are Watts?


Watts, on the other hand, measure the amount of electrical power consumed by a light bulb. In the past, wattage was used as an indicator of brightness because traditional incandescent bulbs had a direct correlation between wattage and brightness. The higher the wattage, the brighter the bulb. However, with the arrival of energy-efficient lighting technologies, the relationship between wattage and brightness has changed.

The Converter from Wattage to Lumens



Energy-efficient lighting options such as LED and CFL bulbs produce more light while using fewer watts compared to traditional incandescent bulbs. This means that wattage is no longer a reliable indicator of brightness. Instead, lumens provide a more accurate measurement of the actual light output of a bulb. For example, a 60-watt incandescent bulb may produce around 800 lumens, while a 10-watt LED bulb can produce the same amount of light.

Understanding Lumens per Watt


To understand how energy-efficient a light bulb is, we can calculate the lumens per watt ratio. This ratio tells how much light (in lumens) a bulb gives out for each watt of energy it uses. Different bulbs have different ratios.

For example, traditional incandescent bulbs, which we’ve used for many years, have a low lumens per watt ratio, around 15 lumens per watt. So, for each watt of energy they use, they only give out 15 lumens of light.

On the other hand, LED bulbs, a newer type of bulb, have a much higher lumens per watt ratio, between 75 and 110 lumens per watt. This means they are much better at turning energy into light, making them more energy-efficient. Choosing LED could save a lot of energy over time.

How to Convert Lumens to Watts


If you’re thinking of replacing an old light bulb with a newer, energy-saving kind, you might want to convert lumens to watts. Lumens tell you how much light a bulb gives off, and watts tell you how much power it uses. Knowing this can help you pick a more energy-saving bulb for your home or work.

To do this, you need to know about the bulb’s luminous efficacy. This tells you how many lumens you get for each watt the bulb uses. It’s a really useful thing to know as it lets you see how good a bulb is at turning electricity into light.

There’s a formula you can use to convert lumens to watts. It’s a handy tool for anyone wanting to pick the best lighting while keeping their power use low.

Watts = Lumens / Luminous Efficacy

For example, if a bulb has a luminous efficacy of 100 lumens per watt and produces 1000 lumens of light, the calculation would be:

Watts = 1000 lumens / 100 lumens per watt
Watts = 10 watts

This means that the bulb consumes 10 watts of power to produce 1000 lumens of light.

Lumens to Watts Conversion Chart



The process of converting lumens to watts, which may initially seem complex, can be greatly simplified with the aid of a conversion chart. This valuable tool provides a clear and easy-to-understand reference for making these conversions with various types of light bulbs. The conversion chart we’ve provided below serves as a general guideline that enables you to convert lumens to watts for different types of bulbs, extending from traditional incandescent to modern LED bulbs. This is a versatile tool that can help you understand the energy efficiency of your light bulbs and make more informed decisions about your lighting choices.

Lumens Incandescent Watts Halogen Watts CFL Watts LED Watts
450 40-60 25-45 9-13 6-9
800 60 45 13-15 8-12
1100 75-100 60-75 18-25 13-18
1600 100 90-100 23-30 16-20
2600 150 145 30-55 25-28
5000 300 275 55-75 40-45

please note that the values given here are only rough estimates. They can change depending on the bulb type and the manufacturer. Different companies might have different details. Even in one company, different bulb models might vary. So, always check the product’s packaging or the manufacturer’s details for the most precise and current conversion information. This way, you’ll have the right information to make a good decision.

Choosing the Right Light Bulb


When selecting light bulbs for your home or office, it is important to consider both lumens and watts. Lumens will help you determine the brightness level you desire, while watts can give you an idea of the energy consumption and efficiency of the bulb. It’s also important to consider other factors such as color temperature, CRI (color rendering index), and the specific requirements of the space you are lighting.

Here are some tips to help you choose the right light bulb:

1. Assess the brightness needed: Consider the purpose of the lighting and the desired level of brightness. For task lighting, you may need higher lumens, while ambient lighting may require lower lumens.

2. Check the packaging: Look for the lumen rating on the bulb packaging. This will give you an indication of the bulb’s brightness. Compare it to the recommended lumen range for your specific lighting needs.

3. Consider energy efficiency: Look for bulbs with a high lumens per watt ratio. LED bulbs are typically the most energy-efficient option, providing more lumens per watt compared to traditional incandescent or CFL bulbs.

4. Pay attention to color temperature: Color temperature is measured in Kelvin and determines the warmth or coolness of the light. Lower Kelvin values (around 2700K) produce warm, yellowish light, while higher values (around 5000K) produce cool, bluish light.

5. Consider the bulb lifespan: LED bulbs have a longer lifespan compared to incandescent or CFL bulbs. This means they will last longer and require fewer replacements, saving you money in the long run.

When selecting light bulbs for any space, there are several key factors to keep in mind. First and foremost, remember the importance of striking a balance. This balance is between three crucial elements: brightness, energy efficiency, and the unique needs of your space. Brightness is important because it directly affects how well you can see and perform tasks. Energy efficiency, on the other hand, can significantly impact your electricity bill and environmental footprint. Lastly, the specific needs of your space come into play. For instance, a home office might require different lighting than a cozy living room. By carefully considering all these factors, you can make an informed decision that both suits your needs and contributes to a more sustainable future.



Lumens and watts are both important measurements when it comes to selecting the right light bulb. Lumens indicate the brightness of a bulb, while watts measure the power consumption. With the advancement of energy-efficient lighting technologies, lumens have become the standard unit of measurement for brightness. Converting lumens to watts can help you choose the right bulb for your needs and ensure energy efficiency. Consider factors such as color temperature, CRI, and the specific requirements of your space when selecting light bulbs. By understanding the relationship between lumens and watts, you can make informed decisions and create the desired lighting ambiance in your home or office.

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