How the daily water need is worked out
A daily water need is the body weight times a per-kilogram basis. This tool does not stop there: when wet food is part of the diet it subtracts the water already in that food, so the figure you read is what still has to come from the bowl.
The basis follows the 50 to 60 mL/kg/day band widely used as the maintenance requirement that keeps urine output normal, offered as a low, middle and high option. Because other sources give other values, a custom field sits beside it, and weights entered in pounds are converted to kilograms internally. Content is current as of October 2026.
The tool works out needs and shortfalls only; it does not grade how dehydrated an animal is, which a separate checklist tool covers. Heat, exercise, illness and medication all shift the real requirement. This tool is for reference only and does not replace veterinary care. Contact your veterinarian right away if you notice symptoms or suspect a problem.
Frequently asked questions
That band is widely used as the maintenance water requirement that keeps urine output normal. Some sources give 60 to 80 mL/kg for dogs and 40 to 60 for cats, so this tool keeps 50 to 60 as the default range and also accepts a custom basis.
Wet food carries a lot of water, so a good share of the daily need arrives with the meal and bowl drinking can look low. The tool subtracts the water in the food and shows what is still left to drink.
A sudden rise or fall in intake can point to kidney or endocrine disease. Measure the daily intake for a few days, write it down and show those figures to your veterinarian.