The complete guide
When to Stop Drinking Coffee Before Bed
Everything that decides your caffeine cutoff — dose, timing, and your personal half-life — in one place. Start with your own numbers, then go deeper.
By Vadim Semenko
Built the caffeine half-life engine · 9 min read · Updated June 2026
Can I still have caffeine — or has my cutoff passed?
Bedtime
What you’ve had
205 mg
95 mg
Key takeaways
- There’s no universal cutoff — it depends on the dose, your bedtime, and your personal half-life (which ranges 3–9 hours).
- Aim for under ~50 mg of caffeine left in your system at bedtime.
- A standard coffee usually needs ~6–8 hours to clear below that line; a 200 mg energy drink needs far longer.
- Genetics (CYP1A2), pregnancy, smoking and oral contraceptives all shift your half-life — so personalize it.
Why a single rule doesn’t work
“Stop caffeine 6 hours before bed” is a population average, not your number. Two people can drink the same coffee at the same time and have wildly different amounts left at midnight — because the enzyme that clears caffeine, CYP1A2, varies several-fold between individuals. The guides below break down each piece.