Rabbit Water Intake Calculator

This free rabbit water intake calculator estimates how much water your rabbit should drink each day from its weight, diet and the weather. It uses the vet standard of 50–150 ml per kg, checks whether your rabbit is drinking a healthy amount, and shows how much hydration comes from its food.

Rabbits are big drinkers for their size: a 2 kg rabbit can get through 100–300 ml a day — as much as a 10 kg dog. Enter your rabbit’s details below for its own range.

How much your rabbit should drink a day, adjusted for diet and weather.




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to drink per day

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In fl oz
From bowl
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Total water need
Food + drink
50–150
ml per kg
The rule

Measured how much your rabbit drank? Check if it’s a healthy amount.



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hydration status

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Healthy range
For this weight
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Your rabbit
Drank
Watch trends
Best check
Day to day

How big a bowl or bottle, and how often to refill it.



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refills needed

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Daily need
High end
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Your vessel
Holds
Bowl > bottle
Best vessel
Rabbits prefer

Feeds lots of greens? See how much water comes from food, not the bowl.



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water from greens

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Total need
Per day
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Left to drink
From bowl
~90%
Greens are
Water

The full daily water chart by rabbit weight.

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daily water by weight


How the Rabbit Water Intake Calculator Works

The rabbit water intake calculator multiplies your rabbit’s weight by the vet guideline of 50 to 150 ml of water per kilogram per day, then adjusts for diet and weather. So a 1 kg rabbit needs about 50–150 ml, a 2 kg rabbit about 100–300 ml, and a 3 kg rabbit about 150–450 ml a day. How much of that a rabbit actually drinks from its bowl depends on diet: one eating dry hay and pellets drinks near the full amount, while one eating lots of wet leafy greens gets much of its water from food and drinks far less. Hot weather, nursing and high activity all push the need toward the top of the range.
Rabbit weight In pounds Daily water (ml) Daily water (fl oz)
1 kg ~2.2 lb 50–150 ml 1.7–5.1 fl oz
2 kg ~4.4 lb 100–300 ml 3.4–10.1 fl oz
3 kg ~6.6 lb 150–450 ml 5.1–15.2 fl oz
4 kg ~8.8 lb 200–600 ml 6.8–20.3 fl oz
Always provide fresh water 24/7. These are healthy ranges — a big swing up or down in how much your rabbit drinks is an early warning sign worth a vet’s attention.

How Much Water Does a Rabbit Drink Per Day?

A rabbit drinks roughly 50 to 150 ml of water per kilogram of body weight each day — about 10% of its body weight. For a typical 2 kg (4.4 lb) rabbit that is 100 to 300 ml a day, which is a lot for a small animal: as much as a 10 kg dog gets through. The exact amount swings with diet (dry food means more drinking), weather (hot days mean more), and activity. Enter your rabbit’s weight in the calculator above for its specific range, in both millilitres and fluid ounces.

How Do I Calculate My Rabbit’s Daily Water Intake?

The formula is simple: body weight in kg × 50 to 150 ml = daily water range. So a 1.5 kg rabbit needs about 75 to 225 ml, and a 3 kg rabbit about 150 to 450 ml. To measure what your rabbit actually drinks, fill its bottle or a bowl to a known level, note the amount, and check again 24 hours later (top up from a measuring jug so you know how much went in). Then compare it to the calculated range using the Hydration Check tab. Remember that a rabbit eating lots of wet greens will legitimately drink less from the bowl.

How to Tell If a Bunny Is Thirsty or Dehydrated

A thirsty or dehydrated rabbit may drink eagerly when offered water, but the clearer signs are physical: thick or sticky saliva, small and hard or fewer droppings, lethargy, a loss of appetite, and skin that stays “tented” for a moment when gently pinched at the scruff instead of springing back. Dark, strong-smelling or very little urine is another clue. Dehydration in rabbits is an emergency because it goes hand in hand with gut stasis, where the digestive system slows or stops. If you suspect dehydration — especially if your rabbit has also stopped eating or passing droppings — see a rabbit-savvy vet straight away.

Can a Rabbit Drink Too Much Water?

Yes. Drinking consistently more than about 150 ml per kg a day is called polydipsia and can be a red flag. An occasional big day in hot weather or on a dry diet is nothing to worry about, but if your rabbit is regularly draining its bottle far beyond the expected range, it can point to kidney disease, bladder problems, diabetes or dental pain, and sometimes to stress or boredom drinking. Pair it with the urine: large volumes of pale urine alongside heavy drinking warrant a vet visit. The Hydration Check tab flags when an intake is above the normal range for your rabbit’s weight.

How Long Can a Rabbit Go Without Water?

Not long. A rabbit should never go more than about 24 hours without water — and far less in heat. Without water a rabbit quickly stops eating, and once a rabbit stops eating its gut can shut down (gut stasis), which can be fatal within a day or two. This is why a water bottle that has jammed or a bowl that has been tipped over is a genuine emergency, not a minor inconvenience. Check the water supply every day, and if your rabbit hasn’t drunk or eaten for 12 hours or more, treat it as urgent and call a vet.

Frequently Asked Questions

Why is my rabbit not drinking water?
The most common reasons are a jammed or dripping bottle, a dislike of the bottle (try a heavy ceramic bowl), or a diet rich in wet greens that already provides moisture. Check the water source works, offer a bowl, and if your rabbit also stops eating or passing droppings, treat it as urgent and call a vet.
Can rabbits drink tap water?
Yes. Ordinary tap water that is safe for you is fine for rabbits, and filtered water is also fine. Avoid giving distilled water as the only source long term, since it lacks minerals. Fresh, clean water at room temperature is what matters most.
Can rabbits drink from a bowl or only a bottle?
Both work, but a heavy, tip-proof ceramic bowl is usually better: rabbits drink more and more naturally with their head in a normal position, whereas sipper bottles deliver water slowly and can jam. Many owners offer both a bowl and a bottle.
How much water does a baby rabbit need?
Nursing kits get all their fluid from their mother’s milk and should not be given water. From weaning (around 3 to 4 weeks) a baby rabbit needs fresh water available at all times, at the same 50 to 150 ml per kg rate — just a smaller total because they weigh less.
Can rabbits drink milk?
No. After weaning rabbits cannot digest milk and cow’s or other animal milk can cause serious digestive upset. Adult rabbits only need water. Orphaned kits are the one exception and need a specialist milk replacer under a vet’s guidance, never cow’s milk.
How often should I change my rabbit’s water?
Every day. Empty, rinse and refill the bowl or bottle daily with fresh water, even if it isn’t empty, to stop bacteria, algae and debris building up. In hot weather check it more than once a day so it never runs dry.

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PetCalculatorHub Editorial Team
This rabbit water intake calculator uses the widely cited veterinary range of 50–150 ml of water per kg of body weight per day (about 10% of body weight), adjusted for diet (dry hay-and-pellet diets mean more drinking; greens-heavy diets mean less, as greens are about 90% water) and for warmth and activity. The hydration and “too much water” thresholds follow the same range, with sustained intake above it flagged as possible polydipsia. These are general guidance, not veterinary advice; sudden changes in drinking, or signs of dehydration or gut stasis, need a rabbit-savvy vet.
Last updated: October 2026