Caffeine & Sleep Tools

Practical calculators that help you plan caffeine timing and minimize sleep disruption — without hype. Estimates are based on caffeine half-life logic and widely cited sleep guidance.

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Caffeine Cutoff Time

Find the latest time you can have caffeine so your bedtime level stays below a target.

Open calculator Why 6 hours matters

Caffeine Levels (Multiple Doses)

Enter multiple drinks and visualize your estimated caffeine curve — including bedtime remaining.

Open calculator Timeline guide

Caffeine Clearance

Estimate when your caffeine drops below a chosen threshold (e.g., 25mg) after your last intake.

Open calculator Sensitivity guide

Credibility, without medical claims

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

Many sleep resources recommend avoiding substantial caffeine within ~6 hours of bedtime, since it may still reduce sleep quality. This site provides educational estimates to help you plan, not diagnose or treat anything.

Is this accurate for everyone?

Caffeine metabolism varies a lot between people. That’s why each calculator lets you choose a sensitivity tier (half-life).

Why do you use half-life?

Half-life is a simple model for how quickly caffeine tends to decline. It’s a useful estimate for planning cutoff time.

Medical disclaimer