Caffeine Clearance Calculator

Estimate how long it takes for your caffeine to drop below a chosen threshold (e.g., 25mg). Educational estimate — not medical advice.

Time to threshold Sensitivity tiers Simple + useful

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

Use this tool to plan earlier timing when sleep matters.

Current caffeine (mg)

If unsure, use your last drink’s estimate.

Sensitivity (half-life)

Threshold (mg)

Lower threshold = more conservative.

Start time

Used to show the clock time you’ll cross the threshold.

FAQ

What does “threshold” mean?

It’s the caffeine level you’d like to be below. 25mg is a conservative default for many people.

Why might reality differ?

Metabolism varies, and caffeine intake isn’t always a single clean dose. Treat results as planning guidance.