How much caffeine is still in your system at bedtime?
Log what you drank and when. This works out how much caffeine is still circulating when your head hits the pillow.
1 Add what you drank today
Tap a drink below, or search for the exact one. Then drag the slider to the time you had it.
Nothing logged yet. Add a drink and the curve appears.
2 Tell us your bedtime
3 Here is what is left
0 mg
still circulating when you go to bed
Still active
0mg over the sleep threshold Caffeine still circulating at lights out is linked with less deep sleep and more waking through the night, even when falling asleep feels normal.
Add a drink to see your day
To stay under 50mg at 23:00, one more coffee would need to land by —.
You are already over 50mg at 23:00, so there is no room for another coffee today.
Caffeine figures are indicative and vary by brand, serving and preparation. This is an estimate, not medical advice.
You logged {day}.
Your {drink_time} {drink} is {drink_pct}% of what is still in you at bedtime.
One more coffee would need to land by {cutoff} to keep you under {threshold}mg at {bedtime}.
You are already at or over {threshold}mg at {bedtime}, so there is no room for another coffee.
You are already below where the programme starts.
You are on {total}mg a day. Reset opens at {opening}mg, so there is nothing here for the kit to bring down. At this level the timing of your last drink matters more than the total.
You are already inside the range the kit was built for.
You are on {total}mg a day. The programme opens at {opening}mg, so day one is a cut of about {pct}%.
You are on {total}mg a day. The programme opens at {opening}mg and steps down from there, five days at a time: {opening}, then 120, 80, 40, then no added caffeine.
Why {opening}mg? It is about two coffees, so day one is a step down rather than a stop. Reset then drops 40mg every five days, a quarter of the opening dose each time, which sits inside the 10 to 25 per cent every few days that tapering studies use. High enough to hold a heavy habit, and well under the 400mg a day treated as the ceiling for healthy adults.
Reset carries the caffeine and comes down by capsule count across 20 days. Flow stays at two a day for all 30, including the ten days after the caffeine has gone.
See the kitUK made, GMP certified, ships in 2 to 3 days, 30-day refund on unopened items.
This is the part the kit is built for.
You are on {total}mg a day. Reset opens at {opening}mg and comes down by capsule count over 20 days, five days at a time, until there is no added caffeine left.
That is above the 400mg a day UK and EU food safety guidance treats as the ceiling for healthy adults.
Why {opening}mg? It is about two coffees, so day one is a step down rather than a stop. Reset then drops 40mg every five days, a quarter of the opening dose each time, which sits inside the 10 to 25 per cent every few days that tapering studies use. High enough to hold a heavy habit, and well under the 400mg a day treated as the ceiling for healthy adults.
Withdrawal usually begins 12 to 24 hours after the last dose and is at its worst over the first two days. Coming down in steps spreads that out instead of taking it in one go.
See the kitUK made, GMP certified, ships in 2 to 3 days, 30-day refund on unopened items.
Worth knowing anyway
Not ready yet?
Not ready yet?
We write about caffeine timing, sleep and tolerance. Nothing to buy until you need it.
We will send you the 30-day schedule so you can read it properly first.
We will send you how the 30 days actually run, so you can read it properly before you decide.
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Now bring that number down
You have just seen what is still in you at bedtime. Reset takes your caffeine down by capsule count over 20 days, and Flow holds your new caffeine-free baseline for the ten days after that.
UK made, GMP certified, ships in 2 to 3 days, 30-day refund on unopened items.
How this is worked out
Caffeine’s half-life is about five to six hours, so around half a dose remains six hours later and roughly a quarter six hours after that. The tool projects each drink through your day, estimates what may be left at bedtime, and shows your peak level. The 50 mg line is a practical threshold for the tool, not a medical limit.
Why your own number will vary
Caffeine content swings widely by brand, bean, grind and brew time, so two flat whites are rarely the same drink. How fast you clear it varies between people as well, largely for genetic reasons, and it is slower in pregnancy and with some medications. Treat the figure as an estimate to think with rather than a measurement.
What actually moves it
Two things: how much, and how late. Moving your last drink earlier changes the bedtime figure the same day, which is the quicker win. Bringing the daily total down is the slower one, and stepping the dose down over weeks is generally easier to hold than stopping outright.
