Water, well timed.
Enter your weight, your daily activity, the climate and your waking hours, and the planner turns them into a water target in litres, US fl oz and 250 ml glasses, set against the EFSA reference. It then spreads the glasses across your day and lets you tick them off as you drink, with today's count kept in your browser.
Your target for today, glass by glass.
Move the sliders and the target updates as you go. Then tick each glass as you drink it: today stays in your browser and the count starts fresh tomorrow.
The baseline is 30 ml of fluid per kg of body weight.
Adds 350 ml for every 30 minutes of deliberate movement: sport, a brisk walk, gardening.
Climate today
Hot and humid adds 10 percent for the sweat you lose at rest.
Pregnancy or breastfeeding
Adds 300 ml in pregnancy and 700 ml while breastfeeding.
Your waking hours
The glasses are spread between these two times, the last one about an hour before bed.
EFSA sets an adequate intake of 2.0 l a day for women and 2.5 l for men as total water, with roughly 20 to 30 percent of it coming from food.
- Body weight70 kg × 30 ml
- 2.10 l
- Activity30 min at 350 ml per 30 min
- + 0.35 l
- Climatetemperate, no addition
- + 0.00 l
- Pregnancy or breastfeedingneither
- + 0.00 l
Today, glass by glass
16 h awake, 10 glasses: about one every 1 h 40 min.
0 of 10 glasses, 0 percent of your target.
How it works.
- Set your weight, your activity minutes, the climate and, if it applies, pregnancy or breastfeeding, plus your wake and bed times.
- Read the target in litres, US fl oz and 250 ml glasses, see where it sits against the EFSA reference and how each part adds up.
- Tick each glass as you drink it: the tracker spreads the glasses across your day, keeps today in your browser and shows the percent reached.
How the target is built
The planner starts with a rule of thumb that dietitians use for healthy adults: about 30 ml of fluid per kilogram of body weight a day, which gives 2.1 l for 70 kg and 2.7 l for 90 kg. It then adds 350 ml for every 30 minutes of deliberate activity, roughly what a moderate workout loses as sweat, and 10 percent more in hot and humid weather, where you keep sweating at rest. Pregnancy adds 300 ml and breastfeeding 700 ml, the extra amounts named by the European Food Safety Authority. The reference line on the result comes from the EFSA scientific opinion of 2010 on dietary reference values for water: an adequate intake of 2.0 l a day for women and 2.5 l for men as total water from drinks and food, of which roughly 20 to 30 percent arrives with food. Soup, fruit and vegetables count, and so do tea and coffee. The planner counts what you drink, which is why its number usually sits above the food-inclusive EFSA figure once activity and heat are added.
Why the timeline matters more than the total
Thirst is a late signal, and it fades with age: from about 60 the sensation weakens while the kidneys concentrate urine less well, so older adults can lose 1 to 2 percent of body weight in water before they feel thirsty. Spreading 8 to 12 glasses across the waking hours removes the guesswork, and the first glass on waking replaces what 7 to 8 hours of breathing and sweating took overnight. The simplest check is urine colour: pale straw means you are on track, dark amber means you are behind. Skin keeps the same rhythm. The radiance guide explains why water and sleep show on the face before any cream does, the clear skin guide counts hydration among its five points, and the dry lips guide shows what a heated room does to the thinnest skin you have.
What this tool is not
The Hydration Planner is a rule-of-thumb estimate for healthy adults, not a medical calculation. Anyone with a heart, kidney or liver condition, anyone taking diuretics and anyone told to restrict fluids should follow the figure from their doctor, not this one. More is not better: several litres within an hour or two can dilute blood sodium, a condition called hyponatraemia that endurance athletes reach when they drink far beyond their sweat loss, and about 1 l per hour over several hours is the usual warning line. Aim at the target across the day, add a glass when you sweat more, and stop when the glasses are done. The tool stores today's glasses and your last settings in your browser only.
Frequently asked.
Do tea and coffee count towards the target?
Yes. EFSA counts every drink towards total water, and moderate caffeine, up to about 400 mg a day or roughly four cups of coffee, does not act as a diuretic in people who drink it regularly. Water remains the better habit because it brings no sugar with it.
Why is my target higher than the EFSA reference?
The EFSA figures of 2.0 l and 2.5 l describe total water, including the 20 to 30 percent that comes from food. The planner counts drinks only and adds activity, heat, pregnancy or breastfeeding on top, so 2.4 l or more for an active 70 kg adult is expected.
How big is one glass?
One glass in the planner is 250 ml, a standard tumbler. A 500 ml bottle counts as two glasses, a large mug of tea as about one and a half.
Does the tool store my data?
Only in your browser. Today's glasses are saved under a key with today's date, your last settings under a second key, and nothing is sent anywhere. Reset today clears the glasses; clearing your browser data removes everything.
What if I work nights or sleep late?
Set your real wake and bed times. A window that crosses midnight, say 20:00 to 11:00, is handled like any other, and the glasses are spread across those 15 hours.
Can I drink too much?
Yes. Healthy kidneys pass about 0.8 to 1 l per hour, so drinking well beyond that for several hours can dilute blood sodium. Spread the glasses across the day and treat the target as the ceiling for an ordinary day rather than a floor.
Guides behind this tool
Skin and Cosmetics
Radiance: what comes before cosmetics
Skin and Cosmetics
Clear skin: five points that count
Skin and Cosmetics
Dry lips: why they crack firstMore tools
The Hydration Planner estimates a fluid target for healthy adults from a rule of thumb; it does not diagnose dehydration and does not replace the fluid advice of a doctor, especially for heart, kidney or liver conditions. This page is for general information and does not replace medical or professional cosmetic advice.