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Calcimator

Light Exposure Calculator

Calculate your daily light exposure in lux-hours for optimal circadian entrainment.

Inputs

min
min
min
lux
hrs

Results

Total Lux-Hours

20,500

% of Recommended68%
AssessmentModerate — Consider more morning light
Evening Melatonin Delay45 min
Evening Light Impact8 / 10
Extra Light Box Needed57 min
How to Use This Calculator
  1. Enter the light intensity in lux for your primary daytime environment.
  2. Set the number of hours spent in bright light and dim light each day.
  3. Input your target bedtime and wake time.
  4. Review the Circadian Alignment Score and recommended outdoor light exposure duration.
  5. Adjust indoor lighting levels until the score improves for better sleep quality.

How the result changes with Afternoon Outdoor Time

Afternoon Outdoor TimeTotal Lux-Hours
3020,500
10546,750
19578,250
270104,500

What each input means

Morning Outdoor Time
Minutes spent outdoors in the morning
Afternoon Outdoor Time
Minutes spent outdoors in the afternoon
Light Box Time
Minutes using a therapy light box
Light Box Intensity
Lux rating of your light box
Evening Screen Time
Hours of screen time after sunset
Season
Current season (affects natural light intensity)

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Morning Outdoor Time = 20, Afternoon Outdoor Time = 30, Light Box Time = 0, Light Box Intensity = 10000 = 6 input(s) provided
  2. Calculate Total Lux-Hours
    Total Lux-Hours
    20500 = 20500
  3. Calculate % of Recommended
    % of Recommended
    68 = 68
  4. Calculate Assessment
    Assessment
    Moderate — Consider more morning light = Moderate — Consider more morning light

Engine last updated . Checked against 3 independently-derived tests — how we verify calculators.

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