Dog Water Intake Calculator (how much should my dog drink?)

Understanding the dog water intake calculator — concept and principle

This calculator shows how much water a dog typically drinks per day for its weight, the minimum suggested by its food energy, and where a measured intake sits against the threshold for excessive thirst. Owners use it when a dog seems to drink a lot more or less than usual, or before a vet visit.

Is the dog drinking a lot?: with the default inputs the result is 65 mL/kg (above typical, below 100).

How it is calculated

Typical daily intake = 40–60 mL per kg of body weight.
Minimum by food energy = about 1 mL of water per kcal eaten (NRC, 2006), from all sources including food.
Excessive-thirst threshold = 100 mL per kg per day.
Measured intake per kg = water drunk in 24 hours ÷ weight.
The measured figure is classed as below typical (under 40), typical (40–60), above typical but below the threshold (60–100), or over 100 mL/kg.

The principle

Water need follows body size and energy use, because metabolism produces heat and waste that need water to remove. A dog that eats more calories, exercises, pants in the heat or feeds puppies needs more. Food counts as water too: wet food is about three-quarters water, so a dog on wet food drinks less from the bowl, and dogs on dry food often drink a little more. Drinking more than about 100 mL/kg a day is called polydipsia and can be a sign of illness such as diabetes or kidney or hormone disease.

Worked example

Default inputs: 10 kg dog, 550 kcal a day, measured intake 650 mL in 24 hours.

Typical range = 40 × 10 to 60 × 10 = 400–600 mL.
Minimum by food energy = 550 mL.
Threshold = 100 × 10 = 1,000 mL.
Measured = 650 ÷ 10 = 65 mL/kg.
65 is above 60 but below 100: above typical, below the threshold.

How to read the result

Where does your result fall?

A result slightly above typical is common on warm days, after exercise, or on dry food. Repeated readings over 100 mL/kg, a sudden change in drinking, or more urination than usual are reasons to see a vet. Very low intake can matter too, especially with vomiting, diarrhoea or hot weather.

Common mistakes

Measuring for only part of a day; measure a full 24 hours.
Forgetting water lost from spills or drunk from puddles and toilets.
Comparing a dry-food dog with a wet-food dog.
Limiting water to reduce accidents; never do this without veterinary advice.

Keep in mind: This is not a diagnosis. Always leave fresh water available. See your vet if your dog drinks much more or less than usual.

Frequently asked questions

How much water should a dog drink per day?

Usually about 40–60 mL per kg of body weight, so 400–600 mL for a 10 kg dog.

When is a dog drinking too much?

More than about 100 mL/kg a day is called polydipsia and should be checked by a vet.

Do dogs on wet food need less water?

They drink less from the bowl, because wet food is about three-quarters water.

Sources: National Research Council (2006), Nutrient Requirements of Dogs and Cats (National Academies Press) · Zanghi B. M. & Gardner C. L. (2018), Frontiers in Veterinary Science 5:317

Checked 9 Nov 2026. Typical intake 40–60 mL/kg/day and the 100 mL/kg/day polydipsia threshold (Dr Brian Collins, Cornell Riney Canine Health Center): American Kennel Club, “Why Is My Dog Drinking So Much Water?”; 1 mL per kcal minimum (NRC, Nutrient Requirements of Dogs and Cats, 2006) and 63–73 mL/kg/day on dry food: Zanghi B. M. & Gardner C. L. (2018), Frontiers in Veterinary Science 5:317.

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