CaffSenseWhen Should You Stop Drinking Coffee Before Bed?
Short answer: most sleep guidance points to 6–10 hours before bedtime. But the right cutoff is personal — it depends on your bedtime, the drink, and how fast you clear caffeine.
What the guidelines say
- The American Academy of Sleep Medicine suggests avoiding caffeine at least 6 hours before bed.
- A widely cited 2013 study (Drake et al.) found caffeine 6 hours before bed still measurably reduced sleep.
- Some newer research suggests sensitive sleepers stop 8–9 hours before bed.
If your bedtime is 11 pm, a 6-hour rule means a last coffee by 5 pm; a 9-hour rule means by 2 pm.
Why a fixed rule isn't enough
Caffeine's half-life ranges from about 2 to 8+ hours between people. Two people drinking the same latte at 3 pm can have very different amounts left at midnight. A rule of thumb ignores your dose size and your metabolism.
A better approach: a personal cutoff
Most people sleep best with under roughly 50 mg of caffeine still active at bedtime. If you know your bedtime and your usual drink, you can work backwards to the latest time you can have it and still be under that threshold. That's exactly what the CaffSense calculator computes — and what the app refines from your own Apple Health sleep over time.
| Bedtime | ~6 h cutoff | ~9 h cutoff |
|---|---|---|
| 10:00 pm | 4:00 pm | 1:00 pm |
| 11:00 pm | 5:00 pm | 2:00 pm |
| 12:00 am | 6:00 pm | 3:00 pm |
Practical tips
- Switch to decaf or tea after your cutoff — tea has roughly half the caffeine of coffee.
- Watch hidden sources: energy drinks, pre-workout, and some sodas.
- Track for a week or two; patterns are easier to see than to guess.
Sources
- Drake et al. (2013) — caffeine 0/3/6 h before bed reduced sleep.
- Sleep Foundation — how long caffeine takes to wear off.
- FDA — caffeine guidance.
This article is observational wellness information only, not medical advice, and should not be used to diagnose, treat, cure, or prevent any condition.