One question, answered
About CoffeeCutoff
“Avoid caffeine late” is not very useful when you are deciding whether to order one more coffee. CoffeeCutoff turns your bedtime and drink into a specific last-coffee time you can use today.
What time should I stop drinking coffee if I still want to sleep well tonight?
What your cutoff means
Your result estimates the latest time to have your selected drink and reach the calculator's reference point by bedtime. It is a practical starting point, not a promise that coffee before that time cannot affect your sleep.
- Start with the time
- Use the calculated cutoff on an ordinary day.
- Move it earlier
- Choose Sensitive or stop earlier if afternoon caffeine often keeps you awake, or if your drink is larger than the listed serving.
- Know the limit
- This tool cannot diagnose a sleep problem or tell you that a dose is safe for a medical condition.
What goes into the estimate
CoffeeCutoff uses your bedtime, drink, quantity, and selected caffeine sensitivity. It estimates caffeine fading over time with a half-life model and a shared 50 mg reference point. The reference is a product rule for producing a useful time, not a medical safety threshold.
See the calculation and researchWhat happens to your inputs
The calculation runs in your browser. You do not need an account, and CoffeeCutoff does not save a personal coffee history. If you share a result link, that link contains the choices needed to recreate your result.
Read the terms and privacy detailsOne decision, explained clearly.
Find my last coffee time