Hydration
Water Intake by Body Weight
A simple per-kilogram rule that gets most people to a sensible hydration target.
5 min read·Updated 25 June 2026
HG
HealthGood Editorial Team
Last updated 25 June 2026
Reviewed by HealthGood Editorial Standards Board
A reasonable baseline is 30–35 ml of fluid per kilogram of body weight per day, adjusted up for hot weather and exercise.
Quick reference
- 55 kg (121 lb) — about 1.65–1.9 L
- 70 kg (154 lb) — about 2.1–2.45 L
- 85 kg (187 lb) — about 2.55–3.0 L
- 100 kg (220 lb) — about 3.0–3.5 L
Frequently asked questions
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References
- World Health Organization — Body mass index (BMI). https://www.who.int
- NHS — Healthy weight and BMI. https://www.nhs.uk
- Centers for Disease Control and Prevention (CDC) — Healthy Weight, Nutrition, and Physical Activity. https://www.cdc.gov
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure. Am J Clin Nutr (1990).