Water Intake Calculator — How Much Water Should YOU Drink?

How to use

1. Enter weight — kg or lb, pick your unit.
2. Add activity & climate — exercise minutes per day and whether you're in a hot climate.
3. Get your target — liters per day plus glasses and bottles to actually hit it.

General information only — not medical, financial or legal advice. Figures cross-checked against public official sources (IRS / HMRC / NHS / WHO guidance); content last reviewed September 2026. For decisions that matter, confirm with a licensed professional in your country.

About this tool

The old “8 glasses” rule ignores body size and lifestyle. The evidence-based baseline is ~30–35 ml per kg of body weight, plus ~500–600 ml per hour of exercise and 10–20% more in hot climates. This calculator applies exactly that — including a gymnastic-free adjustment for AC life vs Gulf summers — and converts the target into glasses (250 ml), US cups and common bottle sizes so “drink more water” becomes a countable number.

FAQ

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