Daily Water Intake Calculator for Pets
Get a realistic daily water target for your dog or cat, in millilitres, cups, and fluid ounces — and learn what a change in drinking can mean.
Hydration is a quiet health signal
Water drives everything from temperature control to kidney function, and pets are good at hiding early illness. Knowing roughly how much your companion should take in gives you a baseline — so a real, sustained change stands out instead of slipping by.
Treat the result as a range, not a quota. The point isn’t to make your pet hit an exact number, but to notice when drinking drifts well above or below what’s normal for them and to keep clean water easy to reach.
Frequently Asked Questions
How much water does a dog or cat need a day?
As a rule of thumb, dogs need roughly 50–60 ml of water per kilogram of body weight per day, and cats a little less. That total includes moisture from food, so a pet eating wet food will drink noticeably less from the bowl than one on dry food alone.
Does this include water from food?
Yes — the figure is total daily water. Wet and raw diets are around 70–80% water, so they supply a large share of the need; dry kibble is only about 10% water, so those pets top up much more from the bowl. Cats evolved to get most of their water from prey, which is one reason many do better with some wet food.
What makes a pet drink more or less than the estimate?
Hot weather, exercise, body size, lactation, and diet all shift the number, and it's a range rather than a fixed target. A one-off busy or hot day of extra drinking is normal. What matters is your pet's usual baseline and any lasting change from it.
When should increased thirst worry me?
A sudden, sustained rise in drinking and urination is one of the most common early signs of conditions like kidney disease, diabetes, or a hormonal disorder — especially in older pets. If your pet is regularly drinking well above its usual amount for more than a day or two, contact your vet.
How do I encourage a reluctant drinker?
Offer several clean water stations away from food and litter, try a pet water fountain (moving water appeals to many cats), add water or low-sodium broth to meals, and include wet food. If your pet is drinking far less than expected and seems unwell or lethargic, treat it as a reason to call the vet rather than a preference.
Educational estimate only — not veterinary advice. A sudden or sustained change in drinking or urination is a reason to contact your vet.