Your caffeine cut-off, worked out in seconds
Enter your bedtime and see the cut-off times that official sources point to.
Evidence note: Consistent with official guidance (NHS, NHLBI) and one peer-reviewed study.
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What the sources say
- NHS: do not smoke or drink alcohol, tea or coffee at least 6 hours before going to bed.
- NHLBI: caffeine's effects can last up to 8 hours, so an afternoon coffee may keep you awake at night.
One study
A 2013 study in the Journal of Clinical Sleep Medicine gave people 400 mg of caffeine 0, 3 or 6 hours before their usual bedtime and compared it with a placebo. Each timing had significant effects on sleep disturbance, and the authors concluded that caffeine taken 6 hours before bedtime still disrupts sleep, supporting advice to avoid substantial caffeine for at least 6 hours before bed. That dose is a high one, and your own drinks and sensitivity may differ.
Try it for 7 nights
Set a cut-off from the calculator, tick each day you stick to it, and notice how you feel. If you are unsure about caffeine and a health condition, ask your pharmacist or doctor. Pair it with the wind-down routine or the Bedtime Challenge.
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Sources
- NHS: Insomnia
Page reviewed 19 March 2024; checked 2026-10-19 - NHLBI (US National Institutes of Health): Healthy sleep habits
Page updated 24 March 2022; checked 2026-10-19 - Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med 2013;9(11):1195-1200
Peer-reviewed abstract, published 15 Nov 2013; record verified 2026-10-19
Questions
What time should I stop drinking coffee?
The NHS says at least 6 hours before bed; NHLBI notes effects can last up to 8 hours. For a 22:30 bedtime that is 16:30 or 14:30.
Does decaf count?
The sources here do not address decaffeinated drinks; check labels and your own response.
Does alcohol help me sleep?
The NHS lists alcohol among the things to avoid in the 6 hours before bed, and NHLBI says to skip alcoholic drinks before bed.
Next
Join the Bedtime Challenge Open the noise player All sleep habits
Related: Wind-down routine (20 minutes) · A 9pm bedtime