Circadian Rhythm Alignment Calculator

Circadian Rhythm Alignment Calculator

Evaluate how well your daily habits align with your circadian rhythm based on sleep timing consistency, light exposure, meal timing, and activity timing.

1 = highly irregular, 5 = consistent bedtime/wake time
0 = natural light exposure aligns with day/night, positive = later, negative = earlier
1 = irregular meal times, 5 = consistent meal times aligned with daylight
0 = activity during peak energy hours (morning/early afternoon), positive = later, negative = earlier

Formulas Used

The Circadian Rhythm Alignment Score is calculated using a weighted formula assessing sleep timing consistency, light exposure, meal timing, and activity timing.

  1. Light Exposure Score:

    \[ L_{\text{score}} = \max\left(0, 5 – \frac{|L|}{2}\right) \]

    Where \( L \) is light exposure deviation in hours from natural day/night cycle. Score decreases as deviation increases.

  2. Activity Timing Score:

    \[ A_{\text{score}} = \max\left(0, 5 – \frac{|A|}{2}\right) \]

    Where \( A \) is activity timing deviation in hours from peak energy hours. Score decreases as deviation increases.

  3. Raw Circadian Score:

    \[ R_{\text{raw}} = w_1 S + w_2 L_{\text{score}} + w_3 M + w_4 A_{\text{score}} \]

    Where:

    • \( S \): Sleep timing consistency rating (1–5)
    • \( L_{\text{score}} \): Light exposure score
    • \( M \): Meal timing consistency rating (1–5)
    • \( A_{\text{score}} \): Activity timing score
    • \( w_1 = 5 \): Weight for sleep consistency
    • \( w_2 = 5 \): Weight for light exposure
    • \( w_3 = 5 \): Weight for meal timing
    • \( w_4 = 5 \): Weight for activity timing

  4. Circadian Rhythm Alignment Score:

    \[ \text{CRAS} = \max\left(0, \min\left(100, \frac{R_{\text{raw}}}{100} \cdot 100\right)\right) \]

    Normalizes the raw score (0–100) to 0–100. Ratings: Poor (0–25), Fair (25–50), Good (50–75), Excellent (75–100).

Example Calculations

Example 1: Typical Office Worker

Inputs: Sleep Consistency = 4, Light Exposure = 2 hours, Meal Timing = 3, Activity Timing = 1 hour

Calculations:

  • Light Exposure Score: \[ \max\left(0, 5 – \frac{|2|}{2}\right) = \max(0, 5 – 1) = 4 \]
  • Activity Timing Score: \[ \max\left(0, 5 – \frac{|1|}{2}\right) = \max(0, 5 – 0.5) = 4.5 \]
  • Raw Circadian Score: \[ 5 \cdot 4 + 5 \cdot 4 + 5 \cdot 3 + 5 \cdot 4.5 = 20 + 20 + 15 + 22.5 = 77.5 \]
  • Circadian Rhythm Alignment Score: \[ \frac{77.5}{100} \cdot 100 = 77.5 \]
  • Rating: Excellent (75–100)

Result: Circadian Rhythm Alignment Score: 77.5 (Excellent)

Example 2: Night Shift Worker

Inputs: Sleep Consistency = 2, Light Exposure = -4 hours, Meal Timing = 2, Activity Timing = -3 hours

Calculations:

  • Light Exposure Score: \[ \max\left(0, 5 – \frac{|-4|}{2}\right) = \max(0, 5 – 2) = 3 \]
  • Activity Timing Score: \[ \max\left(0, 5 – \frac{|-3|}{2}\right) = \max(0, 5 – 1.5) = 3.5 \]
  • Raw Circadian Score: \[ 5 \cdot 2 + 5 \cdot 3 + 5 \cdot 2 + 5 \cdot 3.5 = 10 + 15 + 10 + 17.5 = 52.5 \]
  • Circadian Rhythm Alignment Score: \[ \frac{52.5}{100} \cdot 100 = 52.5 \]
  • Rating: Good (50–75)

Result: Circadian Rhythm Alignment Score: 52.5 (Good)

Example 3: Optimal Alignment

Inputs: Sleep Consistency = 5, Light Exposure = 0 hours, Meal Timing = 5, Activity Timing = 0 hours

Calculations:

  • Light Exposure Score: \[ \max\left(0, 5 – \frac{|0|}{2}\right) = 5 \]
  • Activity Timing Score: \[ \max\left(0, 5 – \frac{|0|}{2}\right) = 5 \]
  • Raw Circadian Score: \[ 5 \cdot 5 + 5 \cdot 5 + 5 \cdot 5 + 5 \cdot 5 = 25 + 25 + 25 + 25 = 100 \]
  • Circadian Rhythm Alignment Score: \[ \frac{100}{100} \cdot 100 = 100 \]
  • Rating: Excellent (75–100)

Result: Circadian Rhythm Alignment Score: 100 (Excellent)

How to Use the Calculator

Follow these steps to evaluate your circadian rhythm alignment:

  1. Enter Sleep Timing Consistency: Rate consistency of bedtime/wake time (1–5, 1 = highly irregular, 5 = consistent).
  2. Enter Light Exposure Deviation: Input deviation from natural day/night cycle in hours (-12 to 12, 0 = aligned).
  3. Enter Meal Timing Consistency: Rate consistency of meal times (1–5, 1 = irregular, 5 = consistent with daylight).
  4. Enter Activity Timing Deviation: Input deviation from peak energy hours in hours (-12 to 12, 0 = aligned).
  5. Calculate: Click “Calculate Circadian Rhythm Alignment Score” to see the result.
  6. Interpret Result: The result shows a 0–100 score with a rating (Poor: 0–25, Fair: 25–50, Good: 50–75, Excellent: 75–100). If you see “Please fill in all fields,” ensure all inputs are valid.
  7. Share or Embed: Use the share buttons to post results on social media, copy the result, or get an embed code.

Note: This is a simplified model. Actual circadian rhythm alignment depends on additional factors like genetics, chronotype, and environmental cues.