Knowledge Base

Candlepower Vs. Lumens [Differences & Conversion Formula]


How to convert candlepower to lumens causes much confusion. Worry not, I cover why they are different and how to change one to the other.

To be 100% correct when referring to candle power, the term Candela should be used. Believe it or not, candlepower actually became obsolete in 1948. Don’t panic, you are right, it is still commonly referred to and used today.

Read on and I will explain all.

Candlepower To Lumens: What’s The Difference?


Candlepower is a term often used in the retailing of floodlights, spotlights used for security, and even a flashlight. This is because it is used for measuring the luminous intensity of a concentrated beam of light.

Whereas, for a light fixture such as a desk lamp, you would find the number of lumens marked on the packaging. As the number of lumens tells you the brightness and overall efficiency of the lamp overall.

Candlepower And Lumens


Candlepower (Candela)

Candlepower (or candela) refers to the luminous intensity given out in one direction. That is the beam intensity of the light source at its brightest point. In the past, this was measurement was taken using a candle of specified dimensions and construction thus, candlepower.

A Laser, spotlight, and flashlight are all good examples of something that could show a measurement in candlepower. This is because they are the types of light sources that focus the light in one direction when knowing the candela (cd)or candlepower is important to the user.

Bear in mind though, you may also find that it includes the number of lumens as well. You can find a good example of how candlepower is used to describe a product here.

Lumen Rating

A lumen rating given to a light source informs you of how much light is emitted in all directions. The higher the lumen count the brighter the light.

An example of this is the lighting you use in your home. This is because the overall brightness is what is important and not the beam or beam distance. Therefore, lumens are an important consideration to take into account when buying new light bulbs or light fixtures for the home or office.

You will want to use fewer lumens for a small cozy room than you would in a workspace, where a brighter light is required.

Compared to the example I have shown where candlepower has been used to describe a product. Here is a good example of the number of lumens being used to describe a product.

Lumens To Candlepower Conversions


Strictly speaking, it is impossible to determine a precise conversion of lumens to candlepower (or candela). Due to the fact that each type of light measurement is not synonymous nor interchangeable. But fear not, lumens can be converted to ‘Mean Spherical Candlepower‘.

I did think I might do lumens vs candlepower chart, but on reflection, I think the two examples below will tell you all you need. 

Convert Candlepower To Lumens

One candela unit (candle power) is equivalent to 12.57 lumens (lm), two-candela units would be 25.14 lumens, and so on. Meaning that if you have a flashlight with 10 candela (cd) it is about 1257 lumens (lm)

So, 1 million candle power equals how many lumens? The answer! 12.57 million lumens are equal to 1 million candlepower.

Convert Lumens To Candlepower

One lumen is the equivalent of a tiny fraction under 0.08 candela (cd) therefore a flashlight with an output of 600 lumens would have a light intensity of about 48 candelas (cd).

Now, without getting too bogged down in terminology, this means that you have a method (mean spherical candlepower) when working out lumens vs candlepower.

Frequently Asked Questions (People Also Ask)


I hope you now know all you need about converting lumens to candlepower. Below I will answer some of the questions that people often ask me to help you further in your quest for the perfect lighting.

How many lumens is 3 million candlepower?

To work out how many lumens there are in 3 million candlepower simply multiply by 12.57, this is the number of lumens per candle power (candela). Therefore a 3,000,000 cd has a light intensity of approx 37,710,000 lumens (lm).

What is the difference between Candela and lumens?

The difference between a candela and a lumen is the light that is being measured. When a candela number is used you are talking about a concentrated light beam, such as a flashlight or spotlight beam. Whereas lumens measure the overall output of light such as lighting fixtures used in the home.

Which are brighter lumens, or candlepower?

When considering which are brighter lumens or candlepower (candela) you have to remember they are not the same type of light.

Lumens tell the user how bright the overall output of a lightbulb is, whereas candela units (candlepower) are used for giving information on concentrated light beams. As an example, if you have a lamp that is 12.57 lumens you have one candle power.

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