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How much water should a dog drink?
A healthy adult dog needs about 1 fluid ounce of water per pound of body weight a day. Enter your dog's weight to get its number, and optionally what it drank in 24 hours to see whether that's normal.
Your dog's daily water needs will show here.
A guide for healthy adult dogs, not a diagnosis. If your dog's drinking has changed, talk to your vet. Last reviewed October 7, 2026.
How much water a dog needs by weight
The American Kennel Club's rule of thumb is about 1 fluid ounce per pound of body weight a day, which works out to roughly 65 mL per kg. Veterinary textbooks give a normal range of about 20–70 mL per kg a day, so many healthy dogs drink a bit less than the rule.
| Dog's weight | Typical water a day | Excessive if over |
|---|---|---|
| 10 lb (4.5 kg) | 10 fl oz (1¼ cups) | 15 fl oz |
| 20 lb (9 kg) | 20 fl oz (2½ cups) | 31 fl oz |
| 40 lb (18 kg) | 40 fl oz (5 cups) | 61 fl oz |
| 60 lb (27 kg) | 60 fl oz (7½ cups) | 92 fl oz |
| 80 lb (36 kg) | 80 fl oz (10 cups) | 123 fl oz |
| 100 lb (45 kg) | 100 fl oz (12½ cups) | 153 fl oz |
"Excessive" is the usual veterinary definition of increased thirst (polydipsia): more than 100 mL per kg in 24 hours. Some texts use 90 mL per kg for dogs.
What changes how much a dog drinks
- Food: canned food is 60–87% water and dry food only 3–11%, so dogs on wet food drink noticeably less from the bowl.
- Heat and exercise: active days and hot weather raise the amount a dog needs.
- Nursing: mothers feeding puppies need plenty of water; keep it available at all times.
- Puppies: the AKC suggests about half a cup every two hours for young puppies, and ½–1 fl oz per pound a day once they are weaned.
When to call the vet
A dog that suddenly drinks a lot more than usual, or needs to pee much more often, should see a vet. Increased thirst can be an early sign of conditions such as kidney disease, diabetes or Cushing's disease. Even if your dog stays under 100 mL per kg, a doubling of its normal intake is worth a check.
Measuring at home helps your vet: fill the bowl from a measuring jug, note every refill for 24 hours, and subtract what is left. Dogs often drink differently at the clinic, so a home measurement is more useful.
Questions people ask
How much water should a dog drink a day?
About 1 fluid ounce per pound of body weight, according to the AKC. A 40 lb dog needs about 40 fl oz, or 5 cups, a day. Dogs on wet food drink less from the bowl.
How much water is too much for a dog?
Vets usually define excessive drinking as more than 100 mL per kg of body weight in a day, about 1.5 fl oz per pound. If your dog regularly drinks more than that, or twice its usual amount, book a vet visit.
How much water should a puppy drink?
The AKC suggests about half a cup every two hours for young puppies. Weaned puppies need about ½ to 1 fl oz per pound of body weight a day.
Why is my dog drinking so much water?
Hot weather, exercise and dry food all increase thirst. If there's no obvious reason, or your dog is also peeing more, have it checked: kidney disease, diabetes and hormone problems can all cause increased thirst.
How do I measure how much my dog drinks?
Use a measuring jug to fill the bowl and write down each refill for 24 hours. The next morning, measure what's left and subtract it. Enter the result above.
Sources
- American Kennel Club: Is your puppy drinking enough water?
- Merck Veterinary Manual: Nutritional Requirements of Small Animals (water and food moisture)
- Davies Veterinary Specialists: Polydipsia (increased drinking) in dogs and cats
- Behrend, Auburn University: Polyuria and polydipsia, a clinical approach
- VCA Animal Hospitals: Testing for increased thirst and urination
- Purdue Canine Welfare Science: Nutrition for the lactating dog