What This Calculator Measures
Estimate your circadian alignment score based on sleep timing, light exposure, and evening habits.
By combining practical inputs into a structured model, this calculator helps you move from vague estimation to clear planning actions you can execute consistently.
This calculator estimates circadian alignment using timing consistency, light exposure, and evening habits.
How to Use This Well
- Enter timing variance and sleep duration.
- Add morning light minutes.
- Set caffeine cutoff and screen time.
- Review score and shift target.
- Adjust habits gradually.
Formula Breakdown
Score = 100 − timing penalties − habit penalties + light boostWorked Example
- 25 minute bedtime variance and 20 minute wake variance reduce the score.
- 15 minutes of morning light adds a boost.
- Caffeine cutoff at 7 hours keeps penalties low.
Interpretation Guide
| Range | Meaning | Action |
|---|---|---|
| 80–100 | Strong alignment. | Maintain timing and light routines. |
| 65–79 | Good alignment. | Refine screen and caffeine habits. |
| 50–64 | Moderate drift. | Stabilize wake time first. |
| Below 50 | High drift. | Reset with consistent wake time and morning light. |
Optimization Playbook
- Anchor wake time: keep it within 30 minutes.
- Boost morning light: 15–30 minutes daily.
- Reduce screens: dim 90 minutes before bed.
- Move caffeine earlier: aim for 6+ hours cutoff.
Scenario Planning
- Baseline: your current timing variance.
- Improved light: add 15 minutes of morning light.
- Earlier cutoff: shift caffeine 1 hour earlier.
- Decision rule: target 80+ alignment score.
Common Mistakes to Avoid
- Changing bedtime without stabilizing wake time.
- Ignoring screen light late at night.
- Assuming weekend shifts do not matter.
- Making large changes too quickly.
Implementation Checklist
- Choose a fixed wake time.
- Track morning light exposure.
- Reduce late-night screen time.
- Review score weekly.
Measurement Notes
Treat this calculator as a directional planning instrument. Output quality improves when your inputs are anchored to recent real data instead of one-off assumptions.
Run multiple scenarios, document what changed, and keep the decision tied to trends, not a single result snapshot.
FAQ
What is a good alignment score?
Scores above 80 indicate strong circadian alignment.
Why does morning light matter?
It anchors your internal clock and improves sleep timing.
How fast should I shift timing?
Move in 15–30 minute steps to avoid disruption.