A goal built from you
Roughly 30–35 ml per kilo of body weight, banded by age and adjusted for sex, plus an allowance for the steps and workouts you logged today. The whole calculation is below.
Coming soon · Not on the App Store yet
Drink the right
Drink the right
amount of water.
Not a flat eight glasses. Sip Water works out a daily target from your weight, your age and how much you actually moved — then adjusts it based on how the day felt. On your iPhone and on your wrist.
iOS 17+ · watchOS 11+ · No account required
The app
Open it, tap a cup, done.
One tap logs a drink. Everything else on this page happens without you asking.
What it does
A hydration app
A hydration app
that shows its working.
Every number on screen can be traced back to something you can check.
It learns from the week
Each day you can say whether you were still thirsty, felt good, or had too much. Those answers nudge tomorrow's target — slowly, within strict limits, and never more than half a litre either way.
Not everything hydrates equally
Water counts at 100%. Tea, juice, coffee, soda and energy drinks count at 95% down to 89%, and the app tells you so on the screen rather than quietly discounting you.
Caffeine that decays
Coffee at 8am is not coffee at 8pm. Sip Water tracks how much caffeine is still on board, flags the 400 mg daily guideline, and tells you when you will drop back under 100 mg.
Apple Health, both ways
Reads your weight, date of birth, biological sex, steps and workouts to set the goal. Writes what you drink back as Water so your other health apps see it. Both directions are off until you turn them on.
On your wrist, standalone
The Apple Watch app logs drinks with your phone off, out of range or left at home, and syncs up when they meet again. Complications for the watch face and Smart Stack are included.
The goal, in full
No black box. Here is the sum.
The app shows this same breakdown in Settings, line by line, so you can see where the number came from.
| Part of the goal | How it is worked out |
|---|---|
| Baseline | body weight × ml per kg × a small adjustment for sex |
| ml per kg, by age | under 18: 40 · 18–30: 35 · 31–55: 33 · 56–70: 31 · 71+: 30 |
| Adjustment for sex | male ×1.00 · female ×0.95 · other or unset ×0.975 |
| Steps | +30 ml for every 1,000 steps above 4,000 |
| Workouts | +12 ml per minute of logged workout |
| Activity cap | the two above add at most 1,500 ml |
| Learned from feedback | ±40 ml per net vote over 14 days, capped at ±500 ml |
| Final result | rounded to the nearest 50 ml, held between 1,500 and 5,000 ml |
No weight in Health? The app assumes 70 kg and says so on screen. No date of birth? It assumes 35.
This is a general estimate, not medical advice. Climate, illness,
pregnancy, medication and several common cardiac, kidney and endocrine conditions
all change how much fluid is right for you, and none of them are inputs here. If a
doctor has given you a fluid target, set it manually in Settings — a manual goal
overrides every part of the calculation above, including the learning.
Privacy
It has nowhere
It has nowhere
to send anything.
This is not a promise about how we behave. It is a fact about how the app is built.
Sip Water has no backend, no analytics SDK and no network code at all.
There is no account to create, no sign-in screen, no server to sync to, no crash
reporter, no advertising identifier and no third-party SDK of any kind linked into
the app. Your hydration log lives in a single file on your own device.
01
What stays on your phone
Every drink you log, your cups, your weight and date of birth, your daily feedback and your streaks. All of it, all the time.
02
What moves, and where
Two places, both yours: Apple Health, if you switch it on, and your paired Apple Watch over Apple's direct device-to-device link. Neither one involves us.
03
The one honest caveat
If you back your iPhone up to iCloud, your Sip Water data is in that backup, and if you have Health enabled in iCloud, Apple syncs Health for you. Both are your settings, not ours.
The full text is in the Sip Water privacy policy, alongside the Sip Water terms of use.
FAQ
The honest answers.
When can I download it?
There is no App Store listing yet, so there is nothing to tap. The app is built and in internal testing. Email [email protected] with the subject "Sip Water launch" and we will write to you once, when it is live.
Do I need an account?
No. There is no sign-in, no email, no password and no profile on a server. Open it and start logging.
Does it work without Apple Health?
Yes. Health is optional in both directions. If you leave it off, enter your weight and date of birth in Settings and the goal is calculated from those — you just lose the steps and workout allowance.
What exactly does it read from Health?
Body mass, date of birth, biological sex, step count and workouts. That is the whole list, and it only reads them after you turn the switch on.
What does it write back?
One thing: your drinks, as Water. Deleting a drink in Sip Water deletes the matching Health sample too. It does not write caffeine, electrolytes, workouts or anything else.
Does it cost anything?
The build as it stands today has no subscriptions, no in-app purchases and no ads. We have not set pricing for launch, so we are not quoting any.
Does it track alcohol?
Deliberately not. Alcohol is Sip's job, and keeping the two apart keeps this one simple.
Are there reminders?
Yes, local ones, and they are off until you turn them on. You pick the interval between 30 minutes and 4 hours and set quiet hours — 10pm to 7am by default. Nothing is pushed from a server, because there is no server.