A daily water intake chart by body weight — in ounces, cups and litres — as a simple starting guide. ✓ oz · cups · litres
Litres of water per day (baseline, before exercise).
A baseline of about half your body weight in ounces. Add more for exercise, heat, pregnancy or illness.
| Body weight | Ounces / day | Cups / day | Litres / day |
|---|---|---|---|
| 100 lb (45 kg) | 50 oz | 6 cups | 1.5 L |
| 120 lb (54 kg) | 60 oz | 8 cups | 1.8 L |
| 140 lb (64 kg) | 70 oz | 9 cups | 2.1 L |
| 160 lb (73 kg) | 80 oz | 10 cups | 2.4 L |
| 180 lb (82 kg) | 90 oz | 11 cups | 2.7 L |
| 200 lb (91 kg) | 100 oz | 13 cups | 3 L |
| 220 lb (100 kg) | 110 oz | 14 cups | 3.3 L |
| 240 lb (109 kg) | 120 oz | 15 cups | 3.5 L |
| 260 lb (118 kg) | 130 oz | 16 cups | 3.8 L |
A popular, easy rule is to drink about half your body weight in ounces of water each day — so a 160-pound person aims for roughly 80 ounces, about 2.4 litres or ten cups. The old "eight glasses a day" (about 2 litres) is a reasonable average for many adults, but larger bodies simply need more, which is why scaling by weight is more useful. Foods and other drinks also contribute to your total fluid.
Increase your intake when you exercise, are in hot weather, are pregnant or breastfeeding, or are unwell. Good everyday signs you're well hydrated are infrequent thirst and pale-yellow urine. For a personalised target that factors in your activity, use our water intake calculator.
This chart shows US fluid ounces, US cups (8 oz) and litres so it works wherever you are. Readers in the UK, Canada, Australia and the UAE can use the litre column directly; use our volume converter for other units.
Weight-based hydration guides scale intake with body mass, which is more defensible than the familiar "eight glasses a day" — a figure with no clear evidential origin that has survived on repetition. Larger bodies lose more water through respiration and skin, so scaling with mass at least tracks something real.
The larger correction is that food supplies a substantial share of daily water. Fruit and vegetables are largely water by weight, and soups, milk and even coffee count towards intake despite persistent claims that caffeinated drinks are dehydrating at ordinary consumption levels. A chart showing only drinking water therefore overstates what you need to drink.
Exercise, heat and altitude raise requirements well above any baseline table, and sweat carries electrolytes as well as water, which is why replacing large losses with plain water alone can cause its own problems. For most healthy people thirst is a reliable enough guide; the table is more useful as a sanity check than as a target to hit.