Hydration & Water Intake Calculators

Specialised tools for athletes, families, health questions and pets. Each one explains its formula, so you can see exactly how your result is worked out.

Sports

Exercise & Sweat Rate CalculatorTurn a before-and-after weigh-in into your hourly sweat rate, body-mass loss and a rehydration target.Running & Marathon Hydration CalculatorPlan how much to drink per hour and per aid station for a training run, half marathon or marathon.Wrestling Hydration Test CalculatorCheck a urine specific gravity reading against the pass line and find your minimum wrestling weight.

Outdoors

Hiking Water CalculatorWork out how many liters to carry for a day hike based on time on trail, temperature and terrain.

Family

Kids Water Intake CalculatorDaily water needs for babies, children and teens by age and sex, plus extra for sports and active play.Pregnancy Water Intake CalculatorDaily fluid target during pregnancy based on the 3.0 L reference intake, exercise and hot weather.Breastfeeding Water Intake CalculatorEstimate how much to drink while nursing or pumping, based on how much milk you are producing.

Nutrition

Water for Weight Loss CalculatorA daily water goal for weight loss, a pre-meal water plan and the calories saved by swapping sugary drinks.Creatine Water Intake CalculatorCreatine dose for loading or maintenance, daily water target and how much water to mix each scoop in.

Health

Dehydration CalculatorEstimate dehydration severity and fluid deficit from the drop between your usual and current weight.Body Water Weight CalculatorEstimate total body water in liters and as a percentage of body weight with the Watson formula.

Pets

Dog Water Intake CalculatorHow much water your dog needs per day from weight, life stage and diet, with an excessive-thirst flag.Cat Water Intake CalculatorDaily water needs for cats and kittens, and how much of it a wet or dry diet already supplies.