How Much Water Should My Dog Drink? Water Intake Calculator
By the Pets Locally team
Updated 2026
A healthy dog or cat needs roughly 40 to 60 ml of water per kg of body weight a day. That total includes water from food, which is why a pet on pouches or tins can drink very little from the bowl and still be fine. If a dog or cat takes in more than 100 ml per kg a day, vets class that as excessive thirst, so it is worth measuring a day's drinking before you book an appointment. Enter your pet's weight and food below to see the typical range, then add a measured day to check it.
How much should my pet drink a day?
Pouches, tins, trays or raw. Leave blank if your dog eats only dry food. A typical cat pouch is 85 g.
Listed under analytical constituents. Most wet foods are 75 to 82%.
Optional: check a measured day
Measure all the water you put down over 24 hours, including top-ups, with a measuring jug, then measure what is left at the end. If you have more than one pet sharing a bowl, measure them separately.
How much water does a dog need?
The usual rule of thumb is 40 to 60 ml of water per kg of body weight each day. A 10 kg dog therefore needs around 400 to 600 ml, and a 30 kg dog around 1.2 to 1.8 litres. Cats need about the same per kg, but many drink little from a bowl because they get much of their water from wet food.
Why wet food changes the answer
Wet food is mostly water: the moisture figure on most pouches and tins is between 75% and 82%. A cat eating two 85 g pouches a day gets roughly 130 ml of water from its food, which can be more than half of what it needs. A dog on dry kibble gets very little water from its food and has to drink nearly all of it.
When drinking a lot is a problem
Vets generally define excessive thirst (polydipsia) as more than 100 ml per kg a day. If your pet is regularly above that, or you notice it drinking noticeably more than usual, measure a few days with a jug and take the numbers to your vet. They are far more useful than "drinking a lot". Puppies, nursing mothers, very active dogs and pets in hot weather drink more, so judge the trend over several days rather than a single figure.
How to measure a day's drinking
- Pick a 24-hour period when your pet is at home and on its normal routine.
- Fill the bowl from a measuring jug and note the amount. Write down every top-up.
- After 24 hours, pour what is left back into the jug and measure it.
- Enter the total put down and the amount left in the calculator above.
If other pets share the bowl, or your dog drinks from puddles and ponds on walks, the figure will be off. Keep pets apart for the day if you can.
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