Water Intake by Weight — Daily Reference Table
Daily drinking-water targets for adults from 40 to 150 kg, at rest and with moderate activity — generated by the same model that powers the homepage calculator.
Body weight is the single biggest driver of daily water needs. This table applies the calculator's baseline model — about 35 ml of water per kilogram of body weight per day for adults aged 19–64, based on Institute of Medicine reference values — to every weight from 40 to 150 kg in 5 kg steps, then adds the calculator's moderate-activity adjustment (+7%).
Values use the male baseline (factor 1.0). Female needs are about 5% lower (× 0.95), reflecting body composition. Age, pregnancy, breastfeeding, climate, and health conditions change the number further — the calculator personalizes all of it.
| Weight | At rest | Moderate activity (30–60 min) | ||||
|---|---|---|---|---|---|---|
| Litres/day | Cups | Glasses | Litres/day | Cups | Glasses | |
| 40 kg ≈ 88 lb | 1.4 | 6 | 4 | 1.5 | 7 | 5 |
| 45 kg ≈ 99 lb | 1.6 | 7 | 5 | 1.7 | 8 | 5 |
| 50 kg ≈ 110 lb | 1.8 | 8 | 5 | 1.9 | 8 | 6 |
| 55 kg ≈ 121 lb | 1.9 | 9 | 6 | 2.1 | 9 | 6 |
| 60 kg ≈ 132 lb | 2.1 | 9 | 6 | 2.2 | 10 | 7 |
| 65 kg ≈ 143 lb | 2.3 | 10 | 7 | 2.4 | 11 | 7 |
| 70 kg ≈ 154 lb | 2.5 | 11 | 7 | 2.6 | 11 | 8 |
| 75 kg ≈ 165 lb | 2.6 | 11 | 8 | 2.8 | 12 | 8 |
| 80 kg ≈ 176 lb | 2.8 | 12 | 8 | 3.0 | 13 | 9 |
| 85 kg ≈ 187 lb | 3.0 | 13 | 9 | 3.2 | 14 | 9 |
| 90 kg ≈ 198 lb | 3.2 | 14 | 9 | 3.4 | 15 | 10 |
| 95 kg ≈ 209 lb | 3.3 | 14 | 10 | 3.6 | 15 | 11 |
| 100 kg ≈ 220 lb | 3.5 | 15 | 10 | 3.7 | 16 | 11 |
| 105 kg ≈ 231 lb | 3.7 | 16 | 11 | 3.9 | 17 | 12 |
| 110 kg ≈ 243 lb | 3.9 | 17 | 11 | 4.1 | 18 | 12 |
| 115 kg ≈ 254 lb | 4.0 | 17 | 12 | 4.3 | 18 | 13 |
| 120 kg ≈ 265 lb | 4.2 | 18 | 12 | 4.5 | 19 | 13 |
| 125 kg ≈ 276 lb | 4.4 | 19 | 13 | 4.7 | 20 | 14 |
| 130 kg ≈ 287 lb | 4.6 | 19 | 13 | 4.9 | 21 | 14 |
| 135 kg ≈ 298 lb | 4.7 | 20 | 14 | 5.1 | 22 | 15 |
| 140 kg ≈ 309 lb | 4.9 | 21 | 14 | 5.2 | 22 | 15 |
| 145 kg ≈ 320 lb | 5.1 | 22 | 15 | 5.4 | 23 | 16 |
| 150 kg ≈ 331 lb | 5.3 | 22 | 15 | 5.6 | 24 | 16 |
How to read this table
- Litres/day is the same drinking-water (fluid) target the calculator displays: the amount to get from beverages — water, tea, coffee, milk, and other drinks all count toward it. Food moisture is additional to these numbers, not part of them: roughly 20% of total water intake normally comes from food (soup, fruit, vegetables), which is why the calculator's separate total-water figure runs about 25% above the drinks target.
- Cups are 240 ml (US cup); glasses are 355 ml (12 fl oz), the standard glass the calculator visualizes. Counts are rounded up — you meet the target by finishing the last one.
- At rest means little movement and no exertion (the bottom of the calculator's activity slider). Moderate activity is the equivalent of 30–60 minutes of moderate activity, like a brisk walk or a light gym session.
- Intense training, heat, pregnancy, and breastfeeding push needs higher — use the calculator for a personalized target.
A note on safety
These are starting points for healthy adults, not medical advice. Needs vary with health conditions and medications — and more is not better: drinking several litres in a short window can dilute blood sodium (hyponatremia). Spread intake across the day and use thirst and urine colour as your everyday check. Consult a healthcare provider for personal guidance.
Related guides
Model and sources: Institute of Medicine (IOM), Dietary Reference Intakes (2005); WHO, Water Requirements, Impinging Factors, and Recommended Intakes (2003); EFSA, Dietary Reference Values for water (2010); American College of Sports Medicine (ACSM), Exercise and Fluid Replacement (2007). See also our methodology.