If you have compared different red light panels, you have probably seen specifications such as 120 mW/cm², 140 mW/cm² or 160 mW/cm². These values are called irradiance and are used to describe how much light energy reaches the treatment area. The problem is that many manufacturers mention this number without explaining what it actually means.
For anyone wanting to understand the difference between different red light panels, irradiance is one of the most important specifications to know. At the same time, it is also one of the most misunderstood. Many people believe that the highest number automatically means the best panel, but the reality is a little more complicated than that.
In this guide, we go over what irradiance means, why it is measured in mW/cm², and how you can use the information to compare different products in a smarter way.
What is irradiance?
Irradiance is a measure of how much light energy hits a given surface. In red light therapy, it is used to describe how much light actually reaches the body at a certain distance from the panel.
An easy way to understand irradiance is to think of a garden hose. If you direct a powerful stream of water at the ground, a lot of water hits a small area. If you spread the water out over a larger area, the pressure is lower. Light from a red light panel works in the same way.
The higher the irradiance, the more light energy reaches the treatment area in the same amount of time.
However, this does not mean that the highest possible irradiance is always best. As with everything else, it is a matter of balance between several different factors.
What does mW/cm² mean?
Irradiance is normally given in mW/cm², which stands for milliwatts per square centimeter.
It sounds technical, but really it just describes how much light energy hits each square centimeter of the treatment area.
| Irradiance | Simplified description |
|---|---|
| 50 mW/cm² | Lower light intensity |
| 100 mW/cm² | High light intensity |
| 150+ mW/cm² | Very high light intensity |
The important thing is not to memorize the numbers but to understand that they are used to compare how much light reaches the body from different panels.
Why is irradiance measured at different distances?
This is one of the most important things to understand when comparing specifications.
The light from a red light panel spreads out as distance increases. The further away you are from the panel, the larger the area covered by the light. At the same time, the amount of light energy reaching each square centimeter decreases.
Therefore, the same panel can have completely different irradiance values depending on whether the measurement is made at 15 cm, 30 cm or 60 cm.
When comparing different products, it is therefore important to check that the measurements have been taken at the same distance. Otherwise, you risk comparing two numbers that are not really comparable.
Is higher irradiance always better?
It's easy to think that the highest number automatically means the best product. It's not that simple.
Irradiance is an important part of the picture, but it doesn’t tell the whole story. Two panels can have similar irradiance values but still provide different user experiences depending on factors such as treatment area, lens construction, component quality and light distribution.
A panel with slightly lower irradiance but a significantly larger treatment area may be a better choice for many users than a smaller panel with extremely high light intensity.
That's why serious manufacturers look at the big picture and not just a single number.
Irradiance or watts – what is more important?
Many customers first compare wattage because it is a number that feels familiar.
The problem is that watts primarily describe how much electricity the product consumes.However, it says very little about how much light actually reaches the treatment area.
Irradiance therefore often gives a much better picture of the panel's actual performance than wattage alone.
That doesn't mean that watts are unimportant, but when comparing different red light panels, irradiance is often a more useful specification.
How does Infracenter work with irradiance?
When we develop products, we don't just look at a single number. The goal is to create a balance between light intensity, treatment area, component quality and user experience.
That's why the PRO MAX series uses quality components such as Mean Well drivers, Dual Chip LED technology and advanced lenses that help deliver even and efficient light distribution.
We believe that it is more important that the product works well in real life than that it looks impressive in a specification list.
Summary
Irradiance is a measure of how much light energy reaches the treatment area and is one of the most important specifications in red light therapy (RLT).
By understanding what mW/cm² means, it becomes easier to compare different red light panels and to understand why certain products differ in price and performance.
At the same time, it is important to remember that irradiance is only part of the whole. Treatment area, component quality, light distribution and design play at least as much of a role in the overall user experience.
FAQ
What does irradiance mean?
Irradiance describes how much light energy hits a certain surface at a certain distance from the panel.
What does mW/cm² mean?
mW/cm² stands for milliwatts per square centimeter and is used to measure the light intensity from a red light panel.
Is higher irradiance always better?
No. Irradiance is important, but treatment area, component quality and light distribution also play a major role.
Why is irradiance measured at different distances?
Light spreads out as distance increases, so the irradiance value changes depending on how far from the panel the measurement is made.
Is irradiance more important than watts?
To understand how much light actually reaches the treatment area, irradiance is often a more useful specification than wattage.