Drink Water Calculator

Metric uses kilograms and centimetres; US uses pounds with feet and inches; UK uses stones and pounds.
Selects the Dietary Reference Intake life-stage band.
The DRI table gives pregnancy and lactation their own adequate intakes, replacing the age band.
Kilograms (metric), pounds (US) or whole stones (UK). Needed for the per-kilogram and Holliday-Segar methods.
Only used with UK stones-and-pounds: the pounds part, e.g. 11 st 4 lb is weight 11 and extra pounds 4.
The bedside adult rule is 30-35 mL/kg/day. Only used by the per-kilogram method.
The DRI figure is total water including food. In NHANES III beverages supplied about 81 per cent of it, so 0.8 turns the total into an amount to drink.
ACSM: sweat rates run 0.5-2.0 L per hour. 500 mL/h is the low end; weigh yourself before and after training to find your own rate.
There is no published multiplier for climate, so enter an amount you or your clinician have decided on.
Fluid to drink
2,960 mL/day
Daily Water Intake Calculator
Fluid to drink
2.96 L/day
Fluid to drink
100.1 US fl oz/day
Fluid to drink
12.5 8 oz cups/day
Baseline requirement
2,960 mL/day
Added for exercise
0 mL/day
Added for heat, altitude or illness
0 mL/day
Total water including water in food (DRI method)
3.70 L/day
Reference band used
Adults 19 and over
Method used
Dietary Reference Intake (IOM/NASEM 2005)
Worked out from Institute of Medicine (now NASEM), Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate, National Academies Press and 3 other sources.
These are population reference intakes, not a prescription. Heart failure, kidney disease, liver disease and some medications require a fluid restriction rather than a target, and drinking far above requirement can cause dangerous hyponatraemia. Ask a clinician before changing fluid intake for a medical reason.

How this is worked out

3 steps
  1. DRI band: Adults 19 and over. Adequate intake for total water = 3.7 L/day.
  2. Water in food supplies the rest, so the amount to drink = 3700 x 0.8 = 2960 mL/day.
  3. Total to drink = 2960 mL/day = 2.96 L = 12.5 eight-ounce cups

Results are general information, not financial, tax, legal, medical or engineering advice.