Sleep Tax
Hours missed, consecutive short nights, caffeine, and travel load — converted into a fatigue tax and expected drops in reaction time and decision accuracy.
Inputs
Target window used here: 7.5–9.0 hours.
Caffeine after 2pm
Result
28
Mild tax — monitor
- Δ reaction time
- +51 ms
- Δ accuracy
- −2.5%
- Acute debt
- 1.5 h
- Chronic load
- 2.2
8×1.5 + 3.2×3^0.85 + 4×2 + 0 = 28
Methodology
Acute debt is hours below 7.5 last night. Chronic load scales that debt by consecutive short nights with diminishing returns. Travel adds 4 index points per time zone in a 72-hour window. Late caffeine adds a sleep-architecture penalty, not a performance bonus.
acute = max(0, 7.5 − hours) index = clamp(8·acute + 3.2·nights^0.85 + 4·zones + caffeine, 0, 100) ΔRT = 1.8 × index ms Δaccuracy = 0.09 × index %
Limits Coefficients are a transparent synthesis of published sleep-restriction and jet-lag literature, not a clinical instrument and not a team-specific model. Pair with the Travel Fatigue calculator when the road trip is the dominant load.