How much water should a dog drink a day?
This dog water intake calculator estimates how much water your dog needs each day from its weight and life stage, takes off the water already in wet food, and shows the result in millilitres, litres, US cups or fluid ounces. It also lets you check how much your dog is actually drinking against the levels vets use to spot excessive thirst.
The estimate follows a simple rule from canine nutrition research: a dog needs roughly one millilitre of water for every kilocalorie of energy it uses. For a typical neutered adult that works out at about 50–60 mL per kg of body weight a day — around a litre for a 20 kg dog. Puppies, working dogs, nursing mothers and hot weather push the figure up.
Always leave fresh water out. The number here is a guide for noticing changes, not a ration to limit drinking.
How to use the Dog Water Intake Calculator
- Enter your dog’s weight in kg or lb.
- Choose the life stage and activity that fits best.
- If you feed wet food, enter the grams per day and the moisture % from the label.
- Read the daily water need, the amount from the bowl and the level that counts as too much.
- Optional: measure what your dog drinks in 24 hours and enter it to see whether it is in the normal range.
Dog Water Intake Calculator features
Energy-based estimate
Water ≈ 1 mL per kcal, with calories from the same RER × life-stage method vets use.
Wet food counted
Food moisture is subtracted, so you see what should come from the bowl.
Thirst check
Measured intake compared with the 20–70 mL/kg normal range and the 90–100 mL/kg excess levels.
Any unit
Millilitres, litres, US cups or fluid ounces; kg or lb.
Animated bowl
Fills to show the daily need against the level that counts as excessive.
The formula and a worked example
Energy: resting energy = 70 × weight in kg0.75, multiplied by a life-stage factor (1.6 for a neutered adult). Water: about 1 mL per kcal, the conservative requirement from the US National Research Council’s 2006 nutrient guide. A study by Zanghi and Gardner (2018) measured healthy dogs on dry food drinking about 1.2–1.4 mL per kcal — 60 to 82 mL per kg a day — so many dogs drink a little more than the estimate.
Example: a 20 kg neutered dog. 70 × 200.75 = 662 kcal × 1.6 = 1,059 kcal, so about 1,059 mL a day (53 mL/kg, about 4.5 US cups). If it eats 400 g of wet food with 78% moisture, the food supplies 312 mL and about 747 mL should come from the bowl.
How much is too much?
Sources: Davies Veterinary Specialists fact sheet “Polydipsia in dogs and cats” (20–70 mL/kg normal; definitively increased over 100 mL/kg); dvm360, “The ins and outs of polyuria and polydipsia” (over 90 mL/kg in dogs). Checked October 2026. Excessive thirst can be a sign of diabetes, kidney or liver disease, Cushing’s syndrome, high calcium or pyometra.
| Intake per kg per day | 20 kg dog | What it means |
|---|---|---|
| Under 20 mL | under 400 mL | Less than usual — normal on a wet diet, otherwise ask your vet |
| 20–70 mL | 400–1,400 mL | Textbook normal range |
| Above about 90 mL | over 1,800 mL | Excessive drinking by many vets’ definition |
| Above 100 mL | over 2,000 mL | Definitely increased (polydipsia) — see your vet |
Tips for keeping your dog hydrated
For daily food amounts use the dog food calculator; for people, the water intake calculator does the same job.
- Keep at least one bowl of clean water out at all times, and take water on long walks and car journeys.
- Hot weather, exercise, dry food, fever and nursing all raise the amount a dog needs.
- Dogs on wet food drink noticeably less from the bowl — that is normal.
- Measure over two or three days before worrying: one hot day can push intake up.
Dog Water Intake Calculator FAQ
How much water should a dog drink per day?
Roughly 50–60 mL per kg of body weight for a typical adult — about one litre for a 20 kg dog — with a normal range of about 20–70 mL/kg. Use the dog water intake calculator for your dog’s weight and life stage.
How much water should a dog drink in cups?
About one US cup (240 mL) per 10 lb of body weight a day for an average neutered adult; the calculator converts any result to US cups or fluid ounces.
How much water does a puppy need?
More per kg than an adult, because puppies use more energy for growth. A 5 kg puppy under four months needs about 700 mL a day by this method. Give small amounts often and always leave water out.
Why is my dog drinking so much water?
Heat, exercise and dry food are common harmless reasons. If intake stays above about 90–100 mL per kg a day, see your vet — diabetes, kidney disease and Cushing’s are possible causes.
Should I limit my dog’s water?
No, unless your vet tells you to. Restricting water can be dangerous, especially for dogs with kidney disease or diabetes.
Is this veterinary advice?
No. Ask your vet — this is general information, not veterinary advice.