Health & FitnessUpdated May 2026

Water Intake Calculator

Calculate your daily water intake needs based on weight, activity level, and climate for proper hydration.

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Updated 2026

Water Intake Calculator

Use this free water intake calculator to find your daily water target based on weight, activity, and climate.
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How Water Intake Is Calculated

1

Base Requirement

Start with 33ml per kg of body weight — a standard medical recommendation.

2

Activity Adjustment

Exercise increases water loss through sweat. Active people need 15-50% more.

3

Climate & Factors

Hot climates, pregnancy, and illness all increase water requirements.

Signs of Dehydration

  • Mild: Thirst, dry mouth, headache, fatigue, dark urine
  • Moderate: Dizziness, rapid heartbeat, reduced urination, confusion
  • Severe: Requires immediate medical attention

Verified accuracy

Cross-checked against authoritative formulas (IRS, NIST, ACM) and updated for 2025/2026 tax years and rates.

Instant results

No server roundtrip. All math runs in your browser so results appear the moment you finish typing.

Your data stays private

We never collect, store, or transmit your inputs. Every calculation runs locally in your browser.

Learn as you calculate

Each calculator includes the formula, plain-English explanation, and FAQs so you understand the result.

Estimates only. Calculator results are for educational and planning purposes — not professional advice. For binding decisions on taxes, investments, health, or legal matters, consult a qualified professional.

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