ANSI Lumens Vs Lumens: What’s the Difference? and How to Convert Them

Buying a projector used to be so easy. Expensive but simple. These days there are complicated terms and technical jargon that you may think are just salespeople throwing pointless details around to make a sale, but with projectors, these factors are often crucial. One of the most confusing factors is ANSI lumens vs. lumens in a projector. What’s the difference, and which is better?

Lumen is a unit to measure “luminous flux,” or the intensity of the light emitted from the source. ANSI Lumen is the same, but it’s more accurate since it takes more factors into account. There are ways to convert between them. Modern projectors are rated in ANSI Lumens even if it’s not specified. 

Even though modern projectors tend to only rate in ANSI lumens, you may occasionally find one or two (especially by lesser-known brands) who don’t. That’s why it’s essential to understand the difference and how you can convert between the two. But in order for us to understand that, we also have to look at what “lumens” means and how it affects your projector.

What Is ANSI Lumens?

A lumen is a scientific unit that is used to measure “luminous flux.” In simple terms, lumens indicate the brightness or intensity of the light that a projector gives out. This has nothing to do with the brightness on the screen, at least not directly, but it has everything to do with how bright your display is within your surroundings.

Explained simply, higher lumens mean more brightness in a brightly-lit environment. You could also say that lumens are the ability of your projector to resist ambient light in the environment. For example, low lumens are fine if you only use your projector in a dimly-lit or dark room. However, high lumens are a must-have for a brightly-lit room or outside on a sunny day.

Now, to understand ANSI lumens, let’s look at this comparison of different light sources:

  • A candle is equal to approximately 14 lumens
  • A 100-watt lightbulb: 1,600 lumens
  • Sunsets range around 400 lumens
  • The lighting required on a movie set is 1,000 lumens
  • A sunny day can go as high as 100,000 lumens
  • Projectors can range anywhere from 500 to 10,000 lumens

As you can see through this comparison, all of these objects can light up a room but at different intensity levels. The problem is that lumens were never standardized. For example, you get LED lumens that deal with the brightness and intensity of light-emitting diodes. Lasers are some of the most high-intensity light sources you can get, and their lumens ratings are standardized for them.

The problem with this is that a projector with bulbs would have one lumens rating, and an LED projector would have another. The two projectors might indicate the exact same lumens, but since LEDs are more effective at projecting colors, the LED projector would be brighter than the lamp projector.

This is the reason why the American National Standards Institute (ANSI) compiled a standardized set of rules and ratings that encompasses all the different light sources so that we could have one uniform lumens rating to judge all light sources and projectors by. 

ANSI lumens are more detailed and specific than standard lumens. It is measured by reading the light output at nine points around the display screen. The average of this is then calculated, which gives the ANSI lumens rating. Another difference is that ANSI lumen measurement does not depend on the size of the display.

Converting Lumens To ANSI Lumens

The main difference between lumens and ANSI lumens is in the way it’s measured, or more specifically, where it’s measured.

With standard lumens, the light intensity is measured at the source, and that’s why the ratings will always be different. For example, a lightbulb projector with 1,000 lumens will display darker than an LED projector with 1,000 lumens. That’s because, even though the brightness is identical at the source, the intensity of LED is much higher than that of lightbulbs, meaning the light travels better.

Since ANSI lumens are calculated at the destination, the light source does not matter. This makes it difficult to reliably and accurately convert between ANSI lumens and standard lumens because the standard lumens depend on the light source while ANSI lumens don’t.

There are simple ways to convert the values, but keep in mind that these are not always reliable since they are estimated values.

Converting LED Lumens To ANSI Lumens

To convert LED lumens to an approximate ANSI lumens value, use this formula: 

LED Lumens ÷ 2.4 = ANSI Lumens

With this formula, 1,000 LED lumens convert to approximately 417 ANSI lumens, and one ANSI lumen equals 2.4 LED lumens. This shows that ANSI lumens require more intensity than LED lumens.

Converting Lightbulb Lumens To ANSI Lumens

To convert lightbulb lumens (also known as light source lumens) to an approximate ANSI lumens value, use this formula: 

Lightbulb Lumens x 0.04 to 0.06 = ANSI Lumens

The value is between 0.04 and 0.06 because it differs between different manufacturers. Some are more efficient than others.

With this formula, 1,000 lightbulb lumens convert to approximately 60 ANSI lumens, and one ANSI lumen equals about 0.06 lightbulb lumens. This shows that lightbulb projectors have far less intensity than LED projectors and that ANSI lumens require more intensity for the same rating.

How Important Is The Lumens Rating In Projectors?

There are many factors that set certain projectors apart from others, including the light source they use. But generally speaking, there are three crucial aspects to compare between projectors. These are:


Some projectors are better at color mixing and projecting than others. Overall the best color separation comes from LED or laser projectors. The better it is at displaying colors, the better your image will appear.


The resolution has to do with the number of pixels (colored dots) that make up the display. For example, a 1024 x 768 resolution projector’s display will be more precise and crisp than an 800 x 600 display. 


Since lumens rate the intensity of the light, lumens will also determine how well your projector will display in brightly-lit areas like auditoriums, boardrooms, or even outside in the sunlight. Very few projectors are genuinely effective in any of these surroundings. This is because most projectors (especially the cheaper ones) do not have high lumens ratings.

Projectors with about 1,500 or fewer ANSI lumens are great for dark rooms or watching outdoor movies at night. 2,500 to 3,000 ANSI lumens should do nicely for general office or auditorium use. If you require a projector that can properly project a clear image in bright daylight, you should aim for anything between 7,000 and 10,000 ANSI lumens. This will give you adequate light intensity. 


The lumens rating is a crucial measurement unit to determine whether or not a projector will be effective for your purposes. Of all the different lumens ratings, ANSI lumens are the best option to focus on since it gives you the most accurate indication of brightness and intensity. Projectors with higher ANSI lumens are more expensive, but it is well worth the expense if that is what you require.