Water Intake Calculator

Your daily water target from body weight — plus a little extra on active days.

FREE TOOL · WORKS OFFLINE · NO SIGN-UP

Results update instantly as you type.

Drink per day
0 L
Millilitres
0 ml
US cups (240 ml each)
0
8 oz glasses
0

How to Use This Water Intake Calculator

  1. 1.Enter your weight. Pick kilograms or pounds — the calculator converts pounds for you.
  2. 2.Pick your activity level. Active days add 350 ml for sweat lost to exercise or heat.
  3. 3.Read your daily target. Shown in litres, millilitres and familiar US cups.
  4. 4.Spread it through the day. A glass with each meal plus a few between meals beats one huge bottle at night.
  5. 5.Treat it as a guide. Hot weather, illness and heavy training all raise what you actually need.

FAQ

How much water does a 70 kg person need per day?

At 33 ml per kg, 70 kg × 33 ml = 2,310 ml = 2.31 L, which is about 9.6 cups of 240 ml. On active days this calculator adds 350 ml, giving 2,660 ml or 2.66 L.

What formula does this calculator use?

It multiplies body weight in kilograms by 33 ml, then adds 350 ml on active days. Pounds are first divided by 2.20462 to get kilograms.

Do cups, tea and food count toward the total?

Partly. Food and other drinks add fluid, but plain water is the most reliable way to hit the target, and this figure is a daily water goal, not a strict medical prescription.

Is this water intake calculator free?

Yes — 100% free, no sign-up, no limits. Everything runs in your browser; none of your numbers are uploaded or saved.

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