Caffeine Half-Life Calculator

Caffeine has an average half-life of 5 hours. Consuming 200mg at 4 PM means 100mg is still active at 9 PM, interfering with sleep architecture.

Initial Dose (mg) [Espresso ~64mg, Drip ~95mg, Energy Drink ~150mg] Hours Elapsed

JavaScript Required. Fallback logic: 150mg dose. After 5 hours (1 half-life), 75mg remains. After 10 hours, 37.5mg remains. Cut off intake 10 hours before sleep.

Frequently Asked Questions

Is this data saved?

No. This tool runs entirely in your browser. Refreshing the page clears all inputs.

Are there known limitations?

Yes. Mathematical models (like 1RM or Caloric Deficit) are estimates based on standard population averages. Individual metabolic variance is significant.

Common Mistakes

Over-estimating the precision of the output.
Failing to account for non-linear variables.
Relying on estimates instead of empirical testing over time.

Data Note: Baseline formulas sourced from peer-reviewed sports science and metabolic journals, aggregated Q3 2024.