CAFFEINE TIMING GUIDE

How late is too late for coffee?

There is no universal coffee cutoff. Dose, bedtime, metabolism, and sensitivity all change the answer.

Start with the dose, not a rule of thumb

A 400 mg dose six hours before bed is not comparable to one small espresso. In a controlled study, 400 mg taken even six hours before bedtime disrupted sleep. That supports caution with large afternoon doses, but it does not create a universal six-hour rule for every person and drink.

A useful calculation

With a five-hour half-life, 100 mg becomes about 50 mg after five hours and 25 mg after ten. StimTrace works backwards from your selected bedtime and comparison marker to show the latest suggested finish time for the same total dose.

Treat the result as a reference

The marker is deliberately adjustable. It helps you compare days and notice patterns; it is not a promise that sleep will or will not be affected.