How many glasses of water a day

It turns body mass × ml per kg (30–35 band) into daily glasses, with optional climate and glass size. A portion habit estimate — not liters with activity add-ons, and not workout-session hydration.

This page does not give one “healthy” count for everyone. It estimates glasses from weight × ml/kg (default 33). At 70 kg that is 9.24 glasses of 250 ml. Illness, heat, and pregnancy need medical judgment.

Not as a fixed rule for everyone. The calculator compares your result with eight servings of the same glass size. At 70 kg and 33 ml/kg that is about +1.24 versus 8 × 250 ml.

With the default 250 ml glass: 8 × 250 = 2000 ml. With US units and a 240 ml cup (8 fl oz): 8 × 240 = 1920 ml. You can change portion size in options.

The calculator first computes milliliters (mass × ml/kg × climate), then divides by glass size. At 70 kg, 33 ml/kg and 250 ml: 2310 ml, or 9.24 glasses.

The calculator multiplies mass in kilograms by ml per kg, then by climate (×0.90 / ×1.00 / ×1.15) and divides by glass size. At 70 kg, 33 ml/kg, temperate climate and 250 ml: 2310 ÷ 250 = 9.24.

That page’s main result is milliliters and liters, with add-ons for activity, heat, and pregnancy or lactation. Here the main result is glasses from mass × ml/kg — without those add-ons.

That page counts a training-session add-on (for example 5 ml/kg/h or your own sweat rate). Here the whole day is counted in glasses, not training minutes.

They set common ml-per-kg values for an ordinary day. 33 is the middle; 30 is lower, 35 higher. You can also enter your own number.

That is how the calculator rounds: below 10 two places, from 10 upward one. Examples 9.24 and 9.60 use two places.

Default is 250 ml with metric units and 240 ml with US units (8 fl oz cup). The 9.24 examples on this page use 250 ml. You can change the serving in options.

An example 30% / 40% / 30% split of the same glass total. It is not a clinic schedule or a timed drinking order.

No. It is a result from mass × ml per kg. EFSA publishes adequate intake in liters including food water. If you are ill, talk to a clinician.

You enter pounds; the calculator converts them to kilograms before × ml/kg. When you switch units, weight in the field converts kg ↔ lb so the glass count stays the same. The default glass becomes 240 ml unless you set your own.

In a fluid balance, yes, but this calculator does not add them separately. It only shows glasses from mass × ml/kg.

Empty weight: “Enter a value in the weight field.” Zero or negative: “Weight must be greater than 0.” Glass outside 50–1000 ml: “Glass size must be between 50 and 1000 ml.”

Yes. 70 × 33.5 ÷ 250 gives 9.38.

It is a popular educational range for an ordinary day. It is not a single EFSA population liter target.

Icons round to whole glasses only for display. The main numeric result keeps the decimal places from the calculation.

On the daily water requirement page: mass × 33 ml plus activity, optionally heat and pregnancy or lactation.

No. Heat, fever, kidney disease and pregnancy change needs. This is a simple habit estimate, not a prescription.

They set ml per kg to 30, 33 or 35. Same math as the buttons in options — clearer labels on the first screen.

Milliliters are divided by the serving you choose. Default is 250 ml in metric; with US units, 240 ml (8 fl oz cup). You can set about 6 or 12 fl oz.

It multiplies volume: cool ×0.90, temperate ×1.00, hot ×1.15. An approximate multiplier, not a body-temperature reading.

You mark servings drunk in this browser until midnight. Icons round to the goal; the main result keeps decimal places.