What this calculator does
This water intake calculator is built for the moment you need a defensible number — quoting a client, comparing options, or checking someone else's math — not a generic estimate.
Daily water needs depend on body weight and activity.
How to use the Water Intake Calculator
- Enter your values in the fields on the left.
- Results update automatically.
- Use the action buttons to copy, share or print.
The formula
~35 ml per kg + extra for exercise.
Worked example
70 kg, 30 min exercise ≈ 2.8 L.
Common mistakes
- Ignoring climate
- Overhydrating
- Confusing thirst with hunger
When to use it
Use as a starting target — adjust for climate and sweat rate.
Pro tips for the Water Intake Calculator
- Save your favorite scenarios by clicking the star icon — they're stored locally, no account needed.
- For big decisions, run best-case, expected, and worst-case scenarios and compare the breakdowns side by side.
- Copy the result to paste it directly into email, Notion, or a spreadsheet cell.
Frequently asked questions
›Coffee counts?
Yes, mostly hydrating despite mild diuretic effect.
›8 glasses?
Common but not evidence-based rule.
›Signs of dehydration?
Dark urine, headache, fatigue.
›Overhydration?
Rare but dangerous (hyponatremia).
›Electrolytes?
Important during heavy sweat.
›Where does the formula come from?
The formula shown in the "How it works" section is the same one you'll find in standard health & fitness references — no proprietary tweaks or hidden weightings.
›Can I embed the Water Intake Calculator on my site?
Embedding isn't public yet, but you can link directly to this page — the URL is stable and shareable.
Embed this calculator
Drop the Water Intake Calculator into your own site or blog post. Free to use — a small “Powered by CalcPilot” link is appreciated.
<iframe src="https://calcpilot.tools/calculators/water-intake-calculator?embed=1" width="100%" height="720" style="border:1px solid #e5e7eb;border-radius:12px;max-width:720px;" loading="lazy" title="Water Intake Calculator — CalcPilot"></iframe>Related calculators
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