How Much Water Should You Drink by Weight

A daily water intake chart by body weight — in ounces, cups and litres — as a simple starting guide. ✓ oz · cups · litres

✔ Reviewed by the True Value Calc editorial team 🗓 Last updated January 2026 📚 Source: common hydration guidance

Daily Water by Body Weight — Chart

Litres of water per day (baseline, before exercise).

Water Intake Chart by Weight

A baseline of about half your body weight in ounces. Add more for exercise, heat, pregnancy or illness.

Body weightOunces / dayCups / dayLitres / day
100 lb (45 kg)50 oz6 cups1.5 L
120 lb (54 kg)60 oz8 cups1.8 L
140 lb (64 kg)70 oz9 cups2.1 L
160 lb (73 kg)80 oz10 cups2.4 L
180 lb (82 kg)90 oz11 cups2.7 L
200 lb (91 kg)100 oz13 cups3 L
220 lb (100 kg)110 oz14 cups3.3 L
240 lb (109 kg)120 oz15 cups3.5 L
260 lb (118 kg)130 oz16 cups3.8 L

How Much Water Should You Drink a Day?

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.

Litres, Ounces & Cups — US, UK, Canada & Australia

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.

Water Intake — FAQ

A common rule of thumb is about half to two-thirds of an ounce of water per pound of body weight, roughly 2–3 litres a day for most adults. Needs rise with exercise, heat, pregnancy and illness. Thirst and pale-yellow urine are good everyday guides.
Yes — larger bodies generally need more water, which is why the chart scales intake by weight. It is a starting estimate; activity level, climate and diet (foods and other drinks also count) all affect your true needs.
Rarely, but drinking extreme amounts in a short time can dilute blood sodium (hyponatremia), which is dangerous. For almost everyone, spreading normal intake through the day and responding to thirst is safe.
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