Before you set anything in the app, it helps to have a number in mind. Our free water intake calculator gives you a science-based starting point in a few taps, and BigDrink itself can suggest a value based on your personal details when you open its settings — you don't have to guess.
This guide covers the four things that make the goal actually useful day to day: setting it in Settings, logging a glass in one tap, adjusting the cup sizes and quick-add amount to match your habits, and reading how close you are on the main screen.
Steps and screenshots verified against app version: 1.0.4
1Get a starting number
If you're not sure what's realistic, try our water intake calculator first — it factors in weight, activity, and climate. BigDrink offers its own suggested value too: it appears when you open the goal setting in Settings, based on the personal details you've entered. Either number is a starting point, not a rule; you can always change it later.
2Open Settings and set your Daily Goal
Tap the settings icon in the top right corner of the main screen, then open Daily Goal. Enter the number you settled on — the suggested value is already filled in, so you're adjusting it rather than starting from zero.
3Log your first glass with the "+" button
Back on the main screen, tap the "+" button. Pick a preset — 200ml, 350ml, or 500ml — or drag the slider for a custom amount. The entry lands in your water intake history right away, and you can edit or delete it there if you tap the wrong one.
4Adjust cup sizes, quick-add amount, and unit
The default presets won't match everyone's actual cup. In Settings, the default increment controls the quick-add amount used across the main screen, the widget, and Apple Watch, and it accepts anywhere from 50 to 1000ml. If you'd rather track in a different measurement, Unit Settings lets you switch it.
5Check your progress on the main screen
The main screen shows how much you've logged today against your Daily Goal, updating the moment you tap +. Scroll down for today's individual entries, or open Statistics for daily, weekly, and monthly trends.
From here, logging is just a tap and your progress bar tells the story. If you ever switch phones or reinstall the app, your Daily Goal and unit come back through iCloud — but note that the water entries themselves are stored on-device and don't currently sync across devices on their own.