How much water should my dog or cat drink?

Updated October 4, 2026 by Kamal Nasir

An adult dog needs about 40 to 60 ml of water per kilogram of body weight a day, according to the American Kennel Club, so a 20 kg (44 lb) dog drinks roughly 800 to 1,200 ml, or 27 to 41 fluid ounces. The Cornell Feline Health Center says a cat needs about 4 ounces of water per 5 pounds of lean body weight a day, about 52 ml per kilogram, or about one cup for a 10 pound cat, counting the water in its food. Enter your pet's weight below for its own figure, and check a measured day against the 100 ml per kilogram line that vets treat as excessive drinking.

General information, not medical advice. How these guides are made.

Where each figure comes from

Figure	Source
Adult dog: about 40 to 60 ml per kg a day	AKC: Why is my dog drinking so much water?
Adult dog rule of thumb: about 1 fl oz per lb a day	AKC: Is your puppy drinking enough water?
Weaned puppy: 0.5 to 1 fl oz per lb a day; puppy still being weaned: about one-half cup every two hours	AKC: Is your puppy drinking enough water?
Cat: about 4 fl oz per 5 lb of lean weight a day; wet food can contain up to 80% water	Cornell Feline Health Center: Hydration
Excessive drinking: more than 100 ml per kg a day	Davies Veterinary Specialists: Polydipsia in dogs and cats; for dogs, the AKC quoting Brian Collins, DVM, Cornell
1 lb = 0.45359237 kg; 1 US fl oz = 29.5735 ml; 1 US cup = 236.588 ml	NIST SP 811, Appendix B.8

Checked on 4 October 2026. Results are rounded: ml to the nearest 10, fluid ounces to the nearest whole, cups to one decimal. Nothing you enter leaves this page.

How much water a dog needs

The AKC puts a dog's usual intake at about 40 to 60 ml of water per kilogram of body weight a day. It also gives a simpler rule of about one ounce per pound, which works out to about 65 ml per kilogram, a little above that range. Intake moves from day to day with weather, activity and diet, and the AKC says the pattern matters more than any single day.

Davies Veterinary Specialists notes that textbooks give a wider normal range for dogs, 20 to 70 ml per kilogram a day, with marked variation between individuals. Using the AKC range, the calculator gives:

10 kg (22 lb): about 400 to 600 ml a day (14 to 20 fl oz)
20 kg (44 lb): about 800 to 1,200 ml a day (27 to 41 fl oz)
27 kg (60 lb): about 1,080 to 1,620 ml a day (37 to 55 fl oz)

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Puppies

The AKC says weaned puppies generally need between half an ounce and one ounce of water per pound of body weight a day, about 33 to 65 ml per kilogram, so a 10 pound puppy needs about 5 to 10 fl oz (150 to 300 ml). Puppies still being weaned need about one-half cup of water every two hours, the AKC says, and the calculator gives no figure for that stage.

The AKC also notes that puppies are more prone to dehydration than adult dogs, and advises against restricting a puppy's water during the day.

Cats, and the water in wet food

Cornell's Feline Health Center says cats need about 4 ounces of water per 5 pounds of lean body weight a day, about 52 ml per kilogram, so the average 10 pound cat should drink about one cup. The figure is per pound of lean weight, so if your cat is overweight, ask your vet for its ideal weight and enter that. Cornell's guidance gives no separate figure for kittens; ask your vet.

That total includes the water in food. Cornell notes that wet food can contain up to 80 percent water, so cats that eat it may drink less, while cats on dry food take more of their water by drinking. Enter the grams of wet food and the moisture percentage from the label, and the calculator subtracts the food's water: for a 4.5 kg cat, 170 g of food at 78 percent moisture supplies about 130 ml, which leaves about 100 ml from the bowl. Totals by lean weight, including food:

3 kg (6.6 lb): about 160 ml a day in total (5 fl oz)
4 kg (8.8 lb): about 210 ml a day in total (7 fl oz)
5 kg (11 lb): about 260 ml a day in total (9 fl oz)

How to measure what your pet drinks

The AKC says measuring the exact amount every day is not normally practical or necessary, and that keeping a note of drinking habits helps you spot a change. When you want a number, measure a full day:

Fill the bowl with a measured amount of water.
Top up only with measured water, and add each top-up to the total.
After 24 hours, measure what is left and subtract it from the total.
Use one bowl per pet, since a shared bowl cannot be split between pets.
Repeat for a few days, since a single day can mislead.

When drinking more is a reason to see a vet

A Cornell veterinarian quoted by the AKC says excessive drinking, called polydipsia, is generally considered when a dog drinks more than 100 ml per kilogram of body weight a day, about 1.5 ounces per pound. Davies Veterinary Specialists uses the same line for dogs and cats, and adds that some pets drink notably more than usual while still staying under it.

So a clear change from your pet's usual amount is worth telling your vet about even below that line. The AKC lists diabetes, Cushing's disease and chronic kidney disease as the most common causes of excessive drinking in dogs, and only a vet can say what a change means for your pet. The AKC also says never to restrict a dog's water unless your vet advises it.

Keeping a daily record with HydroNest

The AKC says keeping a note of a dog's drinking habits can help you spot anything out of the ordinary.

HydroNest Family Water Tracker has pet profiles for a dog, cat or other companion, with a daily water goal from the pet's weight, based on common veterinary guidance, and a bowl logged with one tap on the same family dashboard as the rest of the household. Only pet-safe drinks are shown. Pet profiles are part of HydroNest Premium. Records stay on your device and in your own iCloud, with no account. HydroNest is a hydration log, not a medical device; for pets, your vet's advice comes first.

Questions people ask

How much water should a cat drink a day?

Cornell's Feline Health Center says about 4 ounces of water per 5 pounds of lean body weight, so a 10 pound cat needs about a cup (roughly 240 ml). That total includes the water in food, and cats on wet food, which can be up to 80 percent water, may drink less from the bowl.

How much water is too much for a dog?

A Cornell veterinarian quoted by the AKC says excessive drinking is generally considered when a dog drinks more than 100 ml per kilogram a day, about 1.5 ounces per pound. A smaller rise can still matter if it is a clear change from your dog's usual amount, so tell your vet.

How do I measure how much my pet drinks?

Fill the bowl with a measured amount, measure what is left 24 hours later, and subtract. Use one bowl per pet, top up only with measured water, and repeat for a few days, since a single day can mislead.