Free Tool

Red Light Therapy
Dosage Calculator

Calculate your optimal treatment time based on your device's irradiance and your therapeutic goal. Evidence-based presets from published clinical research.

Check your device manual for this value.

mW/cm²

Skin Rejuvenation

Stimulates collagen production, reduces fine lines and wrinkles, improves skin tone and texture. Based on Avci et al. (2013) and Barolet (2009).

Dose

10 J/cm²

Wavelength

630-660nm

Penetration

Surface (2-5mm)

J/cm²

Your Treatment Time

2m 47s

10 J/cm² at 60 mW/cm²

Device: Red Light Rejuve RLT Mask

Goal: Skin Rejuvenation

Area: Face

Frequency: 3-5x per week

Session Timer

0:00/ 2:47
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How the Formula Works

Time (s) = Dose (J/cm²) x 1000 / Irradiance (mW/cm²)

D

Dose (J/cm²)

The total energy your tissue needs. Different conditions require different doses, typically 4-60 J/cm².

I

Irradiance (mW/cm²)

Your device’s power density — how fast it delivers energy to your skin. Higher irradiance = shorter sessions.

T

Time (seconds)

How long to keep the light on your skin. This is what the calculator determines for you.

Example Calculation

Using the Red Light Rejuve RLT Mask (60 mW/cm²) for Skin Rejuvenation (10 J/cm²):

Time = 10 x 1000 / 60 = 167 seconds = 2 minutes 47 seconds

Higher-powered devices like ours reach therapeutic doses faster. Lower-powered devices (e.g. 20 mW/cm²) would need ~8 minutes for the same dose.

Red Light Therapy Dosage Guide

Optimal dose depends on your treatment goal. Here's what the clinical research recommends.

ConditionDose RangeWavelength
Skin Rejuvenation & Collagen4-15 J/cm²630-660nm
Wrinkle Reduction8-15 J/cm²630-660nm
Acne & Inflammation8-15 J/cm²415nm + 633nm
Wound Healing4-10 J/cm²630-660nm
Hair Growth4-10 J/cm²630-660nm
Pain & Joint Relief15-50 J/cm²810-850nm
Muscle Recovery20-60 J/cm²810-850nm
Sleep / Circadian3-8 J/cm²630nm
Neuropathy10-30 J/cm²810-850nm

Sources: Avci et al. (2013), Hamblin (2017), Heiskanen & Hamblin (2018). Dose ranges represent aggregated findings from multiple clinical studies.

Wavelengths Explained

Red Light (630-660nm)

Visible red light

  • - Penetrates 2-5mm into skin
  • - Reaches the dermal layer (collagen & elastin)
  • - Best for: skin rejuvenation, anti-aging, acne, wound healing
  • - Most studied wavelength for skincare

Near-Infrared (810-850nm)

Invisible to the eye

  • - Penetrates 5-30mm deep
  • - Reaches subcutaneous tissue, superficial muscles, joints
  • - Best for: pain relief, muscle recovery, inflammation
  • - Often combined with red light for full-spectrum benefits

Why Dosage Matters: The Biphasic Response

Red light therapy follows the Arndt-Schulz law — a biphasic dose response where both too little and too much light produce suboptimal results.

Too Low

No therapeutic effect. Not enough energy delivered.

Optimal

Maximum cellular benefit. Collagen and ATP stimulated.

Too High

Inhibitory effect. Excess light can slow healing.

This is exactly why calculating your dose matters — and why “more is better” doesn't apply to light therapy.

Frequently Asked Questions

Treatment time is calculated using the formula: Time (seconds) = Dose (J/cm²) × 1000 ÷ Irradiance (mW/cm²). The dose is the total energy your tissue needs, and irradiance is how quickly your device delivers it. A higher irradiance means shorter treatment times.

Irradiance (measured in mW/cm²) is the power density of your device — how much light energy hits each square centimetre of skin. Check your device manual or manufacturer’s website. Most quality LED masks range from 15–60 mW/cm². The Red Light Rejuve RLT Mask delivers approximately 60 mW/cm² at skin contact.

For most skin treatments, 4–15 J/cm² is the therapeutic range supported by clinical research. For deeper tissue (pain, muscles, joints), 15–60 J/cm² is more appropriate. With a higher-powered device like ours (60 mW/cm²), you reach these doses faster than with weaker devices. Start with the preset and adjust based on your experience.

Yes — this is called the biphasic dose response. Too little light has no effect, the right amount is therapeutic, and too much can actually inhibit results. This is why calculating your dose matters. For skin, staying under 15–20 J/cm² per session is generally recommended based on published research.

For most goals, 3–5 sessions per week is optimal. Many clinical studies showing positive results used protocols of every other day or 3x per week. Consistency over weeks matters more than daily frequency.

Absolutely. Irradiance drops significantly with distance. At contact (0 cm), you get maximum power. At 15 cm away, irradiance can drop by 50% or more. For LED masks worn on the face, distance is consistent and optimal — one of their key advantages over panels.

Our mask uses a combination of 630nm (red) and 660nm (deep red) wavelengths, which are the most clinically studied for skin rejuvenation, collagen production, and anti-aging. These wavelengths penetrate 2–5mm into the skin, reaching the dermal layer where collagen and elastin are produced.

Red light (630–660nm) penetrates 2–5mm and is ideal for skin concerns — collagen, wrinkles, acne, tone. Near-infrared (810–850nm) penetrates 5–30mm and targets deeper tissue — subcutaneous layers, superficial muscles, and joints. Many devices combine both for broader benefits.

Ready to Start Your Treatments?

The Red Light Rejuve RLT Mask delivers ~60 mW/cm² of clinically effective 630-660nm red light — reaching therapeutic dose levels faster than lower-powered devices. Use the calculator above to find your optimal session time.

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