Romp.
A free tool by Romp  ·  Dog Water Intake Calculator

How much water should your dog drink?

Enter your dog's weight for a daily water target in ounces, cups, and milliliters — plus a plain-English note on when a change in drinking is worth a vet check.

Enter details

One number in. A daily target — and when to worry — out.

40 lb
03   Hot day or heavy exercise?
Quick reference

Daily water, by weight.

Based on ~1 oz per pound per day. Individual dogs vary with diet, weather, and activity.

Body weightWater / dayIn cups
10 lb~10 oz~1.25 cups
25 lb~25 oz~3 cups
50 lb~50 oz~6.25 cups
75 lb~75 oz~9.5 cups
100 lb~100 oz~12.5 cups
Questions

Asked, answered.

How much water should a dog drink per day?

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As a rule of thumb, dogs need about one ounce of water per pound of body weight per day. A 40 lb dog needs roughly 40 oz (about 5 cups). Dogs on wet food drink less; dogs on kibble, or on hot or active days, drink more.

Is my dog drinking too much water?

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A single thirsty day isn't a concern. But a sustained increase — noticeably more than usual for several days, especially with more urination — can be an early sign of issues like kidney disease or diabetes and is worth a vet check. Tracking daily intake makes the change obvious.

My dog isn't drinking much — should I worry?

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Dogs eating wet or raw food get a lot of water from food and may drink little from the bowl. But if a dog suddenly stops drinking, seems lethargic, or shows dry gums, contact your vet — dehydration can escalate quickly, especially in puppies and seniors.

Does exercise or hot weather change how much water my dog needs?

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Yes. Heat, humidity, and heavy exercise can raise a dog's water needs by half or more. Always offer fresh water and let your dog drink freely after activity, in small amounts at a time.