How much water should a dog drink a day? (Chart by weight)
Short answer
A healthy adult dog drinks about 1 ounce of water per pound of body weight per day, roughly 50 to 60 ml per kg. A 50 lb dog needs about 50 oz, a little over 6 cups. Dogs on dry kibble, active dogs and dogs in hot weather need more. Dogs on wet food drink less from the bowl because their food is mostly water.
Daily water chart by weight
| Dog's weight | Water per day | In cups | In litres |
|---|---|---|---|
| 5 lb | 5 oz | about ⅔ cup | 0.15 L |
| 10 lb | 10 oz | 1¼ cups | 0.3 L |
| 20 lb | 20 oz | 2½ cups | 0.6 L |
| 30 lb | 30 oz | 3¾ cups | 0.9 L |
| 40 lb | 40 oz | 5 cups | 1.2 L |
| 50 lb | 50 oz | 6¼ cups | 1.5 L |
| 60 lb | 60 oz | 7½ cups | 1.8 L |
| 80 lb | 80 oz | 10 cups | 2.4 L |
| 100 lb | 100 oz | 12½ cups | 3.0 L |
These are starting points for a healthy adult dog at rest in mild weather. The number that matters most is your own dog's normal, so measure it once (how to do that is below) and watch for changes.
What changes how much water your dog needs
- Food. Dry kibble is about 10% water. Canned food is about 75 to 80% water. A dog that moves from wet food to kibble will drink noticeably more from the bowl, and that is normal.
- Heat and exercise. After a long walk, a run or a hot afternoon, a dog can drink double its usual amount. Offer water after every walk.
- Puppies. Weaned puppies need small amounts often. A common rule of thumb is about half a cup every couple of hours while they are awake, scaled to their size.
- Pregnant and nursing dogs. They need much more than the chart, especially while nursing.
- Senior dogs. Many drink less because getting up is uncomfortable or their thirst drive fades. Others drink more because of kidney changes. Both are worth tracking.
- Medication. Steroids such as prednisone and some diuretics make dogs much thirstier.
How to measure how much your dog actually drinks
- In the morning, fill the bowl or fountain with a measured amount, for example 8 cups.
- Put a second bowl with the same amount somewhere your dog can't reach. This tells you how much evaporates.
- 24 hours later, measure what's left in both. Subtract the evaporation from what's missing in your dog's bowl.
- Repeat for two or three days and average it. One hot day or one long walk will skew a single reading.
In a home with more than one dog, you will get a combined number. That is still useful: divide by total weight and compare it with the chart.
Signs your dog is not drinking enough
- Dry or tacky gums instead of wet, slick ones
- Skin on the back of the neck that is slow to fall back after you gently lift it
- Dark yellow urine, or peeing less often than usual
- Tiredness, thick saliva or sunken-looking eyes
We cover the at-home checks step by step in Dehydration in dogs: the signs, two home checks, and what to do.
When drinking a lot is a warning sign
Vets usually treat more than about 100 ml per kg per day, roughly 1.5 oz per lb, as excessive thirst. The medical name is polydipsia. If your dog's intake jumps well above its normal for more than a day or two, and there is no hot weather, extra exercise or food change to explain it, book a vet visit. Common causes they will look for include kidney disease, diabetes, Cushing's disease, urinary tract infections, a uterine infection called pyometra in unspayed females, and medication side effects.
How long can a dog go without water?
Most dogs can survive about two to three days without water, but that is the wrong number to plan around. Dehydration starts within hours, and organ damage can begin long before day two. A dog that refuses water for 24 hours needs a vet. So does a dog that won't drink for 12 hours while it is vomiting or has diarrhea. Puppies, seniors and small dogs get into trouble faster.
Why dogs drink less than they need
The most common reason is simple: the water is stale. A bowl that sits all day collects dust, hair, food crumbs and saliva. Within a day or two a slippery film forms on the inside of the bowl. That film is biofilm, a layer of bacteria that a quick rinse does not remove. Many dogs walk past that bowl and drink from the toilet, the shower or a puddle instead.
The fix is fresher water. Change it at least once a day, and wash the bowl instead of topping it up. Moving water helps too, because many dogs are drawn to it.
That is the problem we built the Crunchy Fountain around. Instead of running the same water past a filter for days, it has two sealed tanks. The drinking tray drains into the used-water tank and refills from the clean tank every 6, 8 or 12 hours. If your dog drinks the tray dry in between, it refills on its own within 2 hours, or you tap the drain button for fresh water in seconds. There is no filter to replace.
Quick answers
How many cups of water should a 50 lb dog drink a day?
About 6 cups, which is 50 oz or 1.5 litres. More on hot days, after exercise or on an all-kibble diet.
How much water should a 10 lb dog drink?
About 10 oz a day, a little over 1 cup.
Should I leave water out for my dog all day?
Yes, for almost every dog. The exceptions are short and specific: your vet asks you to withhold water before surgery, or you lift a young puppy's water an hour or two before bed while house training.
Is it normal for my dog to drink more in summer?
Yes. Heat and panting use up water fast. A big jump in cool weather, with no change in food or exercise, is the kind of change to raise with your vet.