Water and hydration
How many cups of water should my dog drink a day?
Last updated 23 September 2026 · How we write and check this
Short answer
Using a standard 240 ml (8 fl oz) cup, most dogs need roughly 2 to 2.5 cups of water per 10 kg (22 lb) of body weight per day. A 10 kg dog needs about 2 to 2.5 cups, a 20 kg dog about 4 to 5 cups, and a 30 kg dog about 6 to 7.5 cups, adjusted up for heat, exercise, or a dry food diet.
Converting the standard guide into cups
The 50 to 60 ml per kg guide translates to roughly a quarter cup per kg, since one cup holds about 240 ml. This makes it easy to picture: a 5 kg dog needs a bit over one cup, while a 25 kg dog needs around 5 to 6 cups.
Why cups are a rough measure, not a precise one
Bowls and cups vary in exact volume between households, and dogs do not drink in neat cup increments, so this is best used as a mental shortcut rather than something to measure daily. It is most useful for roughly checking whether a bowl refill pattern looks reasonable for your dog's size.
A simple way to check your own dog
Fill the bowl with a known number of cups in the morning, and see how many are left by evening for a few days running. This tells you your dog's actual pattern far more precisely than any general conversion, and gives you a personal baseline to compare against later.
Key takeaways
- Roughly 2 to 2.5 cups per 10 kg of body weight per day is a useful shortcut.
- One cup holds about 240 ml (8 fl oz).
- Cup measurements are approximate since bowl and cup sizes vary.
- Measuring your own dog's bowl for a few days gives a more accurate personal figure.