Tools

Use the tabs to switch calculators. Each tool also has its own page for bookmarking and search.

Cutoff Levels curve Clearance

Tool 1 · Cutoff time

Tool 2 · Levels (multiple doses)

Tool 3 · Clearance

Based on research showing caffeine can affect sleep even 6 hours before bed

Use conservative settings if you’re sensitive, and treat results as estimates.

Disclaimer

This website is for educational purposes only and is not medical advice. Results are estimates and may not match your personal metabolism.