CAFFEINE CALCULATOR
How much coffee
comes to bed with you?
Three quick questions. See what’s still in your system—and what one swap could change.
QUESTION 1 OF 3
What’s your usual coffee?
Adjust size / shots
QUESTION 2 OF 3
How many a day?
Count your usual coffees. You can adjust individual drinks later.
QUESTION 3 OF 3
When’s your last coffee?
Use an exact last-coffee time
Times from midnight to 3:59 am count as the next day.
YOUR ESTIMATED BEDTIME CAFFEINE
Your coffee could still
be with you at bedtime.
estimated at 10 pm
0 mg daily · your current routine
Caffeine through your day
Estimated mg remaining. Vertical rises mark your drinks.
ritual starts here.30 serves, a self-stirring mug
and a spoon. All in one kit.
Comparison uses Original Blend: 15 mg per 7 g serve.
Fine-tune my estimate
Change individual times or caffeine amounts. Times from midnight to 3:59 am count as the next day.
These are scenarios, not a measurement of your metabolism.
An educational estimate, not a sleep score or a personal safety limit. Individual caffeine clearance and sensitivity vary.
Good to know
Your questions, answered.
How we calculate it
We estimate caffeine remaining from each drink using: dose × 0.5^(hours elapsed ÷ half-life). The default half-life is five hours. For more than one coffee, we space drinks evenly from 8 am to your selected last-coffee time. If the last coffee is before 8 am, we start at 4 am instead. One coffee is placed at your last-coffee time. The assumed schedule is shown with your result and can be edited.
The model assumes immediate absorption and no caffeine carried over from earlier days. It excludes any foods, medicines or drinks you haven’t entered. It cannot predict sleep loss or guarantee a health outcome. The Earthrise comparison replaces your latest entered drink with one 7 g serve of Original Blend at the same time.
How much caffeine is in each coffee?
Our café defaults use an illustrative two-shot, 60 mL espresso base containing 80 mg, from EFSA’s reference. A single 30 mL shot is modelled as 40 mg. These are not tested Australian café averages: beans, dose and extraction vary. Instant starts at an illustrative 70 mg per drink, which you should adjust to your brand and serving. “Other” requires you to enter a caffeine amount. Use a label or café figure when available.
How much caffeine is too much?
The FDA cites 400 mg daily as an amount not generally associated with negative effects for most adults. It is not a target or a personal safe limit. Pregnancy, medicines and health conditions can change suitable intake. Ask a healthcare professional about your circumstances. If reducing caffeine, a gradual reduction may help limit withdrawal discomfort.
Sources and product information
EFSA drink references · FDA guidance · Caffeine pharmacology · Original Blend nutrition panel.
Original Blend: 15 mg caffeine per 7 g serving. Other blends may differ. Sources checked September 2026. This calculator does not send or store your answers.
