Caffeine vs WaterSupport
How can we help?
Email [email protected] and a real person will reply, usually within two working days. Include your iPhone model and iOS version if something isn't working.
The app also has a built-in Guide: open Settings › Help › Guide for step-by-step walkthroughs of every feature.
Common questions
How is active caffeine calculated?
With a one-compartment model: caffeine is absorbed over about 50 minutes and cleared with a half-life of 5.5 hours by default. You can change the half-life on the Sleep tab, or pick a preset such as “Hits me hard” or “Pregnant”. Settings › How we calculate lists every source.
I forgot to log a drink. Can I add it later?
Yes. Tap Log past drink in Quick log, or touch and hold a Quick log drink and choose Log past drink…, then set when you had it.
How do I fix or delete a drink?
In the Log tab, swipe a drink to edit its time or amounts, or to delete it. Tap Select to remove several at once.
Why does my water goal go up after coffee?
After a strong coffee the app pairs a glass of water with it. It's a habit, not a correction: moderate coffee hydrates regular drinkers about as well as water.
The Apple Watch doesn't show my latest drinks.
Open the app on your iPhone once so it can sync, and make sure both devices are nearby with Bluetooth on. Drinks logged on the watch sync back the next time they connect.
Apple Health isn't updating.
Open the Health app › your profile › Apps › Caffeine vs Water, and allow Caffeine and Water. Then turn on Apple Health in the app's Settings.
How do I stop reminders?
Each reminder has its own switch: last coffee on the Sleep tab, planned drinks on the Plan tab, and usual time and place alerts from the bell in Quick log. You can also turn notifications off in iOS Settings.
Medical note
Caffeine vs Water gives general wellness information, not medical advice. If you're pregnant, have a heart condition, or take medication that affects caffeine, check your limits with a professional.