Red Light Therapy Distance Guide: Placement, Mounting and Measuring
Published October 2026. Updated October 2026.
Quick answer
Distance changes how much light power lands on each square centimeter, so the right distance is the one your device manual and spec sheet name. For our panels, the stated irradiance falls as you move back: the FX300 lists 83.5 mW/cm² at 6 inches and 43.3 mW/cm² at 12 inches. Pick one distance, measure it the same way every time, and set your session time from the manual. This guide is arithmetic and setup advice, not a promise about outcomes.
Why distance is the first thing to get right
A light panel does not deliver one fixed amount of light. It delivers an amount that depends on how far your skin is from the LEDs. Every irradiance figure on a spec sheet is tied to a distance, and a figure without a distance tells you very little. If you want the background on that number, start with our guide to what irradiance means.
Distance also decides the practical things people ask about: where the panel hangs, whether you stand or sit, how big a floor marker you need, and how long a session runs. This page is the overview. It explains the principles once, then points to the setup topics in this series.
What AWA stated irradiance looks like by distance
These are the figures published in our FX300 and FX500 irradiance specs guide. The last column is a calculation, not a recommendation: it applies the dose formula J/cm² = mW/cm² x seconds / 1000 to a 10 minute (600 second) run so you can see how distance moves the energy figure.
| Panel | Distance | Stated irradiance (mW/cm²) | Arithmetic for 10 minutes (J/cm²) |
|---|---|---|---|
| FX300 | 1 inch | 220 | 132.0 |
| FX300 | 2 inches | 145 | 87.0 |
| FX300 | 3 inches | 116 | 69.6 |
| FX300 | 6 inches | 83.5 | 50.1 |
| FX300 | 12 inches | 43.3 | 26.0 |
| FX500 | 2 inches | 220 | 132.0 |
| FX500 | 4 inches | 149 | 89.4 |
| FX500 | 6 inches | 94 | 56.4 |
| FX500 | 10 inches | 81.4 | 48.8 |
| FX500 | 12 inches | 73.8 | 44.3 |
| FX500 | 20 inches | 58.6 | 35.2 |
Irradiance figures are AWA stated numbers at the listed distance. The energy column is arithmetic only and does not say how long a session should run. Use the irradiance by distance chart for every listed distance.
The inverse square idea, and why panels do not follow it neatly
The inverse square law says that for a small point of light, intensity drops with the square of the distance. Double the distance and you get one quarter of the intensity. Example numbers for arithmetic only: a point source reading 100 at 10 inches would read 25 at 20 inches and 400 at 5 inches.
A panel is not a point. It is a flat surface covered in many LEDs, and up close you are standing inside the area where those LEDs overlap. Our stated numbers show the effect. Going from 6 inches to 12 inches, a strict point source would drop to one quarter. The FX300 figure drops from 83.5 to 43.3, which is about 52 percent of the starting value. The FX500 drops from 94 to 73.8, about 79 percent. That is a gentler fall than the law predicts, which is normal for a large lit surface.
The practical lesson is simple. Do not use the inverse square law to guess your own irradiance. Use the stated figure for the distance you actually sit at, and regard anything between listed distances as an estimate.
Holding dose steady when you change distance
If you move back, the same minutes deliver less energy. The formula can be rearranged to see how the time would have to change to match an earlier energy figure: seconds = J/cm² x 1000 / mW/cm².
- FX500, arithmetic only: 10 minutes at 6 inches is 56.4 J/cm². To land on the same number at 12 inches (73.8 mW/cm²) the arithmetic gives 764 seconds, about 12.7 minutes. At 20 inches (58.6 mW/cm²) it gives 962 seconds, about 16.0 minutes.
- FX300, arithmetic only: 5 minutes at 6 inches is 25.1 J/cm². At 12 inches (43.3 mW/cm²) the same number takes 579 seconds, about 9.6 minutes.
These are not session recommendations. Your manual sets session time and distance. The dose calculator and the dose formula guide let you check your own numbers.
Where each placement topic fits
This hub connects the setup topics in the series. The table groups them by the question you are likely to have.
| Question you have | Topic in this series |
|---|---|
| How close should I stand? | How close to stand to a red light therapy panel; the inverse square law with example numbers; the panel distance chart |
| Standing, sitting or lying? | Positioning under a panel; facing the panel front, back and side; panel height and angle |
| Where does the panel go? | Door mount, wall mount or stand; over the door mounts; panel stands; measuring wall space |
| What about the room? | Room lighting; reflections and walls; ventilation and cords; humid rooms; small apartments; desk and home gym setups |
| How do I repeat the same distance? | The tape measure method; a floor marker for repeatable distance |
| Does the format change the distance? | Contact devices versus arm's length panels; keeping a steady gap with a handheld device; two panels together; beam angle; face area distance and eye comfort |
Positioning: stand, sit or lie
The best position is the one you can hold still, at the same distance, for the whole session. Standing works well for a panel mounted at body height. Sitting works for a desk or a lower panel. Lying down works if the panel is aimed from above or beside you, but it is the hardest to keep consistent. Whatever you choose, keep the skin you are aiming at roughly parallel to the panel face. Light that arrives at a steep angle spreads over more area and lands more weakly.
If you turn to expose a different side, keep the same gap. Many people move closer to the panel when they turn without noticing, which changes the numbers. A marked spot on the floor solves this.
Mounting: stand, door or wall
| Option | Strengths | Things to check |
|---|---|---|
| Floor stand | Moves between rooms, adjustable height | Stable base, cord routing, floor space |
| Over the door mount | No drilling, easy to remove | Door thickness, panel weight, door must stay closed |
| Wall mount | Permanent, tidy, fixed distance marker | Wall type, stud location, panel weight |
| Tabletop or desk | Small devices at arm's length | Steady surface, cord and screen glare |
Check your panel's manual and product page for what hardware is included and the weight it is rated to hang. If you are unsure about a wall, ask a qualified installer. You can compare panel sizes on the compare AWA devices page.
The room around you
- Lighting: Room lights do not change what the panel emits, but a dim room is more comfortable and makes it easier to keep your eyes closed or shielded.
- Reflections: A light wall or mirror can bounce some light back. We do not publish numbers for that, so do not count on it when you plan a session.
- Ventilation and cords: Leave space around the panel so it can shed heat, and keep cords off the floor where you will stand.
- Humid rooms: Keep electrical devices away from water and follow the manual's guidance on where to use it.
- Eyes: Follow the eye protection instructions that came with your device. Our short guide to eye protection covers the basics.
How to measure distance the same way every time
- Decide where distance is measured from: the LED surface of the panel to the skin you are aiming at, matching how the spec sheet states it.
- Use a tape measure at the first session and note the number.
- Mark the floor with tape at your heel or toe, or fix a string to the mount, so you can find the spot again.
- Check once a week that nothing has shifted, especially with door and stand setups.
Common mistakes
- Reading a spec number without noting the distance it was measured at.
- Assuming the inverse square law gives your exact irradiance for any distance.
- Moving closer to "make it stronger" without changing the session time that the manual gives.
- Measuring from the wall or from the frame instead of the LED surface.
- Changing distance between sessions and then comparing them as if they were the same.
- Hanging a panel on a door or wall that is not rated for its weight.
- Skipping the manual. Your device manual outranks any blog guide for time, distance and eye protection.
Before you use any light device: read the label, follow the device manual, and use eye protection as directed. If you have a medical question, speak to a qualified health professional first. This guide is general information, not medical advice.
Related guides in this series
- What irradiance means on a spec sheet
- AWA FX300 and FX500 irradiance specs
- Dose formula: irradiance, time and energy
- How long a session runs, by the manual
- Time, distance and dose arithmetic
- Session time table and Learning Center
Device pages
Read the full page and label for each device before you use it: AWA FX300 panel and AWA FX500 panel. You can also browse AWA panels.
Frequently asked questions
How far should I sit from a red light panel?
Use the distance named in your device manual and spec sheet. Our stated irradiance figures are given at specific distances, such as 6 and 12 inches for the FX300, so your session should match a distance that has a published number.
Does moving back make the light weaker?
Yes. The stated irradiance falls as distance rises. The FX300 lists 83.5 mW/cm² at 6 inches and 43.3 mW/cm² at 12 inches.
Is the inverse square law accurate for a panel?
Only roughly, and mostly far away. A panel is a flat surface of many LEDs, so up close the stated numbers fall more gently than a point source would. Use the published figure for your distance.
Can I add time to make up for a longer distance?
The arithmetic shows how time and energy trade off, but it does not tell you what session length to use. Your manual sets time and distance.
Do I need a floor marker?
It is not required, but a marker makes it easy to stand in the same place every session, which keeps your distance consistent.
Sources
- FDA: General Wellness policy for low risk devices. January 2026 guidance describing general wellness products as low risk products that promote a healthy lifestyle. It is a policy document, not a statement about any one device.
- FDA: Laser Products and Instruments. Explains laser hazard classes I to IV and labeling, and notes that LEDs are not subject to the federal laser product performance standard.
Regulatory note: select devices carry FDA 510(k) clearance for specific, limited uses. Most light devices are sold as general wellness products. Read each product page and label.
How we create this guide
AWA sells red light therapy devices. We write these guides to explain how devices work and how to choose and use one. This is general information, not medical advice. Read each product page and label. See our editorial standards.