Reaction Time Estimator Formula
Understand the math behind the reaction time estimator. Each variable explained with a worked example.
Formulas Used
Estimated Reaction Time
estimated_rt = max(base_rt + sleep_penalty - caffeine_benefit + fatigue_penalty, 150)Age-Based Baseline
baseline_rt = base_rtTotal Adjustment
total_adjustment = sleep_penalty - caffeine_benefit + fatigue_penaltyVariables
| Variable | Description | Default |
|---|---|---|
age | Age(years) | 30 |
sleep_hours | Sleep Last Night(hours) | 7 |
caffeine_mg | Caffeine Today(mg) | 100 |
hours_awake | Hours Awake(hours) | 8 |
base_rt | Derived value= 200 + max(age - 25, 0) * 1.5 | calculated |
sleep_penalty | Derived value= max(7 - sleep_hours, 0) * 15 | calculated |
caffeine_benefit | Derived value= min(caffeine_mg * 0.05, 20) | calculated |
fatigue_penalty | Derived value= max(hours_awake - 14, 0) * 10 | calculated |
How It Works
Reaction Time Estimation
Average visual reaction time is about 200-250 ms for young adults.
Factors Affecting Reaction Time
| Factor | Effect | |---|---| | Age | +1.5 ms per year above 25 | | Sleep loss | +15 ms per hour below 7 | | Caffeine | Up to -20 ms improvement | | Fatigue (>14h awake) | +10 ms per hour |
Practical Impact
At 60 mph, each 100 ms adds about 8.8 feet of stopping distance.
Worked Example
A 30-year-old, 7 hours sleep, 100 mg caffeine, 8 hours awake.
age = 30sleep_hours = 7caffeine_mg = 100hours_awake = 8
- 01Base RT = 200 + (30 - 25) x 1.5 = 207.5 ms
- 02Sleep penalty = 0 (7 hours is adequate)
- 03Caffeine benefit = 100 x 0.05 = -5 ms
- 04Fatigue = 0 (8 < 14)
- 05Total = 207.5 - 5 = 203 ms
Ready to run the numbers?
Open Reaction Time Estimator