Red-Light Therapy Dosage Calculator

Free tool to calculate optimal session time and energy dose (J/cm²) for your RLT device

Red light therapy (RLT) offers benefits like improved skin health, reduced pain, and faster muscle recovery. Enter any two values and the calculator returns the third. Adjust the optional modifiers for a personalised dose.
Enter any two values to begin…

Dosing Guidelines

  • Safe ranges: <20 J/cm² superficial/skin, 20-50 J/cm² moderate/deep, >50 J/cm² high—use cautiously, 2-3×/wk max.
  • Frequency: Beginners 3-5×/wk, maintenance 2-3×/wk. Start low and monitor response.
  • Red-only limit: <20 J/cm² to avoid over-saturation; NIR preferred for >1 cm depth.

Penetration Factors to Consider (Optional)

Skin reflection: ~40-50 % of light reflects off the skin surface before penetrating, especially for deeper targets. Non-contact panels lose more; skin-contact devices lose less. Enable the checkbox to compensate.

Skin colour: Higher melanin absorbs more red/NIR at the surface, reducing deeper penetration by ~10-20 %. Use the skin-type selector if targeting >1 cm depth.

BMI / body composition: Adipose tissue scatters light; higher BMI may require 5-15 % longer exposures. Default is BMI 25.

Frequently Asked Questions

What is the optimal red-light therapy dose for skin health?

3-15 J/cm² per session, 3-5×/week.

How often should I do red-light therapy sessions?

Start with 3-5 sessions per week, adjust as you respond.

Does skin type affect red-light therapy dosage?

Yes—darker skin may need slightly longer times for deeper targets because melanin absorbs more light at the surface.

This tool is for educational purposes only and is not medical advice. Consult a healthcare professional before starting red-light therapy, especially if you have health conditions.