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
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.
- 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
Frequently Asked Questions
What is a normal reaction time?
Young adults typically have visual reaction times of 200-250 ms. Elite athletes may be as fast as 150 ms. Reaction time naturally slows with age.
How does sleep affect reaction time?
After 24 hours without sleep, reaction time is impaired similarly to a BAC of 0.10%. Even modest sleep loss (1-2 hours) measurably increases reaction time.
Does caffeine actually improve reaction time?
Yes. Moderate caffeine (100-200 mg) has been shown to improve reaction time by 5-20 ms, with effects peaking 30-60 minutes after consumption.
Ready to run the numbers?
Open Reaction Time Estimator