Pet Care Calculators
Pet Water Intake Calculator
How much water should your pet drink each day? This pet water intake calculator estimates your dog's or cat's daily water needs from its body weight and adjusts for whether it eats dry or wet food, since wet food provides a lot of moisture.
Last reviewed: June 2026
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Your result will appear here after you press Calculate.
Estimate only. Hot weather, exercise, illness, and medications all change water needs. Always keep fresh water available.
Formula used
The estimate is based on body weight, with a diet adjustment:
- Total daily water ≈ 50–60 ml per kg of body weight (about 1 oz per pound)
- Bowl water = total need × diet factor (dry 1.0, mixed 0.7, wet 0.45)
- Wet food is roughly 70–80% water, so it covers much of the daily need
Worked examples
30 lb dog on dry food
A 30 lb (13.6 kg) dog needs roughly 25 oz (about 750 ml) of water a day. On dry food, nearly all of that comes from the bowl, so refill a couple of times daily.
10 lb cat on wet food
A 10 lb (4.5 kg) cat needs about 8–9 oz of water a day. On a mostly wet diet, much of that comes from food, so you may see it drink only a little from the bowl — which is normal.
How to use this calculator
- Choose whether you have a dog or a cat.
- Enter your pet's body weight in pounds or kilograms.
- Select its diet — dry, mixed, or wet food.
- Press Calculate to see the estimated total daily water need and how much to expect from the bowl.
Reference chart
| Body weight | Daily water (oz) | Daily water (ml) |
|---|---|---|
| 5 lb (2.3 kg) | 4 oz | ≈ 125 ml |
| 10 lb (4.5 kg) | 8 oz | ≈ 250 ml |
| 20 lb (9 kg) | 17 oz | ≈ 500 ml |
| 40 lb (18 kg) | 33 oz | ≈ 1,000 ml |
| 70 lb (32 kg) | 58 oz | ≈ 1,750 ml |
Frequently asked questions
How much water should my dog drink a day?
A common guideline is about 1 ounce of water per pound of body weight per day (roughly 50–60 ml per kg). A 40 lb dog therefore needs about 40 oz, or 5 cups. Active dogs and hot weather increase the need. Enter your dog's weight for an estimate.
How much water should a cat drink?
Cats need roughly the same per-weight amount — about 50–60 ml per kg per day — but they evolved to get much of their water from prey. Cats on wet food may barely touch the bowl, while cats on dry food should drink noticeably more.
Why does my pet on wet food drink so little?
Canned and pouch foods are about 70–80% water, so a pet eating mostly wet food already takes in much of its daily water through meals. Drinking less from the bowl is expected and is not a concern on its own.
How do I know if my pet is drinking too much or too little?
Watch for a clear change from their normal pattern. Drinking a lot more than usual (and urinating more) can point to conditions like diabetes or kidney disease, while drinking far less can signal nausea or pain. Any marked change warrants a vet visit.
Does this work for puppies and kittens?
The per-weight estimate is a reasonable starting point, but young animals, nursing mothers, and very active pets have higher and more variable needs. Always keep fresh water available and ask your vet if you're unsure.
How can I encourage my pet to drink more?
Provide several clean water bowls, try a pet water fountain (cats especially like running water), add water or low-sodium broth to meals, and include some wet food. If your pet still won't drink, talk to your veterinarian.