How much water does a cat need?
A cat needs about 50 ml of water per kg of body weight per day (roughly 3.5–4.5 oz for a typical 8–10 lb cat). This is the total water need — cats on wet food get much of it from their food and so drink less from the bowl, which is one reason wet diets support urinary health.
Signs of dehydration
- Dry, tacky gums and thick saliva
- Lethargy and reduced appetite
- Sunken eyes; skin slow to spring back when gently lifted
Encourage your cat to drink
- Provide a pet water fountain — many cats prefer running water.
- Use wide, shallow bowls and keep them away from the litter box and food.
- Offer multiple water stations around the home.
- Add water or broth (no onion/garlic) to meals, or feed more wet food.
⚠️ A sudden, sustained increase in drinking is a common early sign of kidney disease, diabetes, or thyroid problems in cats — see your vet if you notice it. This is a general estimate.
Frequently asked questions
My cat barely drinks — is that normal?
If your cat eats wet food, low bowl-drinking can be normal since food provides moisture. If on dry food and drinking little, encourage more water and monitor for dehydration.
Is tap water okay for cats?
Generally yes. If your tap water is heavily chlorinated, filtered water may be more appealing; always keep it fresh and clean.
Related: cat food calculator · dog water calculator · all tools.