Your caffeine cut-off calculator
You will be able to: Find a personal caffeine cut-off time from your usual bedtime (an educational estimate).
The NHS advice is simple: no tea or coffee for at least 6 hours before bed. This tool turns that into a clock time and shows what your usual drinks could still leave in your body at bedtime.
How to use it: set your usual bedtime, pick your usual drink and drag "my last coffee" along the day. The line shows the estimated caffeine left at the average clearing rate; the shaded band shows the range between fast and slow clearers. The dotted line marks your 6-hour cut-off when your drink is before it, and the line of text under the chart always gives your cut-off time.
The quick version, without the tool
Count back 6 hours from your usual bedtime:
| Bedtime | Last caffeine by |
|---|---|
| 22:00 | 16:00 |
| 22:30 | 16:30 |
| 23:00 | 17:00 |
| 23:30 | 17:30 |
| 00:00 | 18:00 |
If you are a slow clearer, or you notice that afternoon coffee still seems to keep you up, move your cut-off earlier. Some people prefer a simple rule such as "nothing with caffeine after lunch", which leaves more margin. That is a practical choice, not official advice.
Write your cut-off down, next to your anchor time from Module 1:
My anchor time is ______. My bedtime is about ______. My last caffeine is by ______.
Next: larks, owls and your timing plan