Free tools
Small tools for a boring habit.
Calculators, converters, charts and trackers — all free, all running entirely in your browser. Nothing is uploaded, and none of them ask for your email.
Work out your target
Start here if you want a number.
- Water intake calculatorYour daily target from weight, activity, climate and altitude — shown in ounces, millilitres, litres, cups and bottles at once.Open tool
- Sweat rate calculatorWeigh in, train, weigh out. Get your litres-per-hour, your fluid deficit, and how much to drink per hour next time.Open tool
- Hiking water calculatorHours, heat, pack weight and climb, turned into litres to carry — and what that weighs on your back.Open tool
- Creatine water calculatorYour baseline target plus the extra your dose asks for, split across the day.Open tool
- Breastfeeding water calculatorBuilt around feeds and pumped volume — the input every general calculator ignores.Open tool
- GLP-1 water calculatorA daily fluid range for semaglutide or tirzepatide, split into small sips — with a week-long log to take to your appointments.Open tool
- Sauna calculatorCalories burned and sweat lost for your weight, sauna type and session — with honest numbers, and how much to drink back afterwards.Open tool
Count it
Bottles, cups, gallons and litres, resolved.
Track the habit
On paper, on screen, or across a challenge.
- Printable water trackerBuild a daily, weekly or monthly water tracking sheet, then print it or save it as an image.Open tool
- 75 Hard trackerAll six daily tasks across 75 days, saved in your browser — with the gallon split into bottles so the water rule is actually trackable.Open tool
- 30-day water challengeOne goal, thirty days, one grid. Saved in your browser.Open tool
- Water reminderA drink reminder that runs in this tab. Set an interval and it nudges you — for as long as the tab stays open.Open tool
Check how it is going
A read on whether any of it is working.
Everything else you drink
Coffee counts, and it counts twice. Electrolytes, per litre.
- Caffeine calculatorHow much caffeine is still in you at bedtime, drawn as a decay curve — plus where you are against the daily limit.Open tool
- Electrolyte drink comparisonPick up to four drinks and see sodium, potassium, sugar, calories and cost side by side at the same volume — because every label uses a different one.Open tool
These tools give general wellness estimates only — they are not medical advice. Fluid needs change with health conditions, medication and pregnancy, so talk to a clinician about yours.