Enter your herd size by animal type and get total daily water needs, recommended tank storage capacity, and backup buffer — instantly, for any farm scale.
Enter the number of animals in each category — leave blank or zero to skip
Number of animals by type
Beef Cattle
head
Dairy Cattle
head
Horses / Mules
head
Pigs / Swine
head
Sheep
head
Goats
head
Poultry (birds)
birds
Other Animals
head
L/head/day
Alpacas, deer, rabbits… enter your own rate; blank uses 25.
Adjustment Factors
⚠ Enter at least one animal count greater than zero to calculate.
WaterTankCalculator.com — Livestock Water Requirements
Your Results
Total Daily Water Need
—
Litres per day
Daily (US Gallons)
— gal/day
Average per Hour
— L/hr
Total Animals
— head
Recommended Tank
— L
Tank (US Gallons)
— gal
Storage Buffer
— days
Base Need (Mild)
— L/day
Temperature Factor
— ×
Suggested Tank to Buy
— L
Recommended Tank vs. Daily Need
📖 How To Use
How to Use the Livestock Water Requirement Calculator
Getting your farm's daily water needs takes less than a minute:
Enter your animal counts
Type the number of animals in each category and pick the class underneath — a milking dairy cow drinks about three times what a dry cow does. Only fill the types you actually have. For animals not listed, use Other Animals and enter your own litres per head per day.
Select your climate condition
Water intake rises sharply with temperature. Pick the typical daily temperature of your hottest period for tank sizing. NDSU Extension's beef cattle table shows intake at 90 °F about 63% higher than at 70 °F, and about 30% lower at 40 °F. For year-round planning, run the calculator twice — once for summer peak and once for winter.
Choose your storage buffer
The buffer sets how many days of water your tank must hold. Choose it from how long your supply could realistically be down — for example, how long a pump repair takes where you are. 3 days is a common minimum; 5–7 days suits borehole-only or remote farms.
Calculate and review results
The primary result shows total daily litres at your chosen temperature. The recommended tank is that daily need × buffer days, and the suggested tank to buy adds 15% for water below the outlet and spillage, rounded up to a typical size. Copy or print the results for your water management plan.
Note: Rates are averages from the Ontario Ministry of Agriculture (OMAFRA) livestock water factsheet, treated here as mild-weather values. Real intake varies with weight, diet (dry hay vs lush pasture), milk yield and water quality. Salty or poor-tasting water can cut intake, which is a welfare problem, not a saving.
📐 The Formula
Livestock Water Requirement Formula
The calculation sums the needs of each animal type, then scales for climate and storage:
Daily Need = Σ (Animal Count × Daily Rate per Head)
Adjusted Daily = Daily Need × Temperature Factor (poultry: × 1.5 when hot)
Tank Size = Adjusted Daily × Buffer Days
Tank to Buy = Tank Size × 1.15, rounded up to a typical size
Each animal class uses the average from OMAFRA Factsheet 23-023 (2023). Goats are not in that factsheet, so their figures come from the Merck Veterinary Manual:
Daily Water Consumption Reference
Animal / Class
Litres/Head/Day
US Gal/Head/Day
Range (L)
Beef cow with calf
55
14.5
43–67
Beef dry cow / bull
38
10.0
22–54
Feedlot 364–636 kg
41
10.8
27–55
Dairy cow, milking
115
30.4
68–155 (rises with milk yield)
Dairy cow, dry
41
10.8
34–49
Horse, ~1,000 lb
32.5
8.6
26–39
Finisher pig 70–110 kg
9
2.4
7.3–10
Lactating sow + litter
20
5.3
18–23
Gestating ewe / ram
5.25
1.4
4–6.5
Lactating ewe + lambs
10
2.6
9–10.5
Goat, maintenance
2.4
0.6
1.5–3.3
Laying hen
0.25
0.07
0.18–0.32
Broiler, summer
0.45
0.12
up to 0.77 at 32 °C
OMAFRA gives poultry per 1,000 birds; shown here per bird. Milking dairy goats need 4–5 times their dry matter intake as water (Merck), which works out at roughly 10 L/day for a typical milking doe — a derived planning figure.
Climate Adjustment Factors
Daily Temperature
Multiplier
Basis (NDSU, 1,000 lb finishing steer)
Cool, ~10 °C / 50 °F
× 0.75
9.4 gal vs 12.6 gal at 70 °F
Mild, ~21 °C / 70 °F
× 1.00
12.6 gal (baseline)
Warm, ~27 °C / 80 °F
× 1.15
14.5 gal
Hot, 32 °C / 90 °F+
× 1.63
20.6 gal
The ratios come from NDSU Extension AS1763, Table 1, and are the same across its growing and finishing cattle and bull classes. The calculator applies them to all mammals as a planning approximation. For poultry it uses OMAFRA's guidance instead: about 50% more water once air temperature passes 30 °C (86 °F).
🌾 When to Use This
Practical Use Cases for Livestock Water Sizing
🏗️
New Farm Setup
Size your storage tanks before you buy them. Calculate peak summer demand, add a 3–5 day buffer, and specify the right tank capacity from day one.
☀️
Drought & Dry Season Planning
Switch to the "Hot" temperature setting and a 7-day buffer to model a worst-case heatwave with a supply failure, and check you have enough backup capacity.
📈
Herd Expansion
Adding 20 beef cattle to an existing operation? Run the calculator with and without the new animals to confirm your current infrastructure is adequate.
💧
Irrigation vs. Livestock Priority
Know exactly how much water livestock claim before allocating the remainder to crop irrigation. Combine with the Irrigation Water Requirement Calculator for full-farm planning.
🔌
Pump & Pipe Sizing
The average per hour (daily ÷ 24) is the minimum your supply must keep up with. Animals drink in bouts — after feeding and in the hottest hours — so the pipe and trough refill rate need to be several times higher. Use the Pump Horsepower Calculator for exact specs.
📋
Compliance & Grant Applications
Many agricultural grants and water licences require documented water demand estimates. Copy and print your results directly from this calculator for formal submissions.
🧮 Worked Example
Worked Example: Mixed Farm in a Hot Summer
A farm with 40 beef cows with calves, 4 horses, 60 lactating ewes and 200 laying hens on a single borehole. Summer days reach 32 °C (90 °F), and the owner wants 5 days of storage.
Animals
Mild (L/day)
Hot (L/day)
40 beef cows with calves × 55 L
2,200
3,586
4 horses × 32.5 L
130
212
60 lactating ewes × 10 L
600
978
200 laying hens × 0.25 L
50
75
Total
2,980
4,851
Five days at mild temperatures is 14,900 L, but in a hot spell it is 24,255 L. With the 15% margin, buy a tank of about 28,000 litres (about 7,400 US gallons). Sizing for the mild figure would leave the farm with about three days of water in a heatwave — exactly when a pump is most likely to be working hardest.
❓ FAQ
Frequently Asked Questions
How much water does a beef cow drink per day?
It depends on her stage and the weather. OMAFRA puts a dry beef cow at about 38 litres (10 US gallons) a day on average (22–54 L) and a cow nursing a calf at about 55 litres (14.5 gallons) (43–67 L). Heat raises this a lot: in NDSU's table, a 1,000 lb finishing steer goes from 12.6 gallons at 70 °F to 20.6 gallons at 90 °F.
How much water do sheep need per day?
A pregnant ewe or ram drinks about 5 litres per day on average (4–6.5 L), and a ewe nursing lambs about 10 litres (9–10.5 L), according to OMAFRA. Feeder lambs of 27–50 kg drink about 4.4 L. Sheep on dry feed or in hot, dry weather drink more, and sheep on lush pasture drink less.
Why is dairy cattle water consumption so much higher than beef?
Milk is roughly 87% water. A dairy cow's water intake follows her milk yield. OMAFRA gives 68–83 L/day for a cow giving 13.6 kg of milk, rising to 132–155 L/day at 45.5 kg; the average for milking cows is 115 L/day, which the calculator uses. A dry cow drinks about 41 L/day. For a high-producing Holstein herd, the top of the range is the safer design figure.
How many days of storage should my farm water tank hold?
Base it on how long your supply could realistically be out. 3 days is a common minimum on a reliable piped supply; 5–7 days suits farms that depend on a single borehole, river pump or rainwater. Remote farms where a repair can take more than a week should plan for 10 days or more, and should size it at hot-weather intake. The calculator's buffer selector lets you model any scenario instantly.
Does hot weather really increase livestock water consumption by 50%?
It can be more than that. In NDSU Extension's beef cattle table, intake at 90 °F (32 °C) is about 63% higher than at 70 °F (21 °C) for growing and finishing cattle and bulls — a 1,000 lb steer goes from 12.6 to 20.6 gallons a day. That is the 1.63× factor this calculator uses for hot weather. For poultry, OMAFRA expects about 50% more water once air temperature passes 30 °C.
How do I calculate water requirements for mixed livestock?
Enter each animal type separately in this calculator and it totals them automatically. For mixed classes of the same species, put the largest group in its field and add the rest under Other Animals with that class's rate from the table. For species not listed (alpacas, llamas, deer), enter their count under Other Animals and type your own litres per head per day; if you leave the rate blank, the calculator uses a general 25 L/head/day.
What size water tank do I need for 50 beef cattle?
For 50 beef cows with calves at 55 L each: 2,750 litres per day in mild weather. A 3-day buffer needs 8,250 litres; with the 15% margin that is about 9,500 litres, so a standard 10,000-litre tank. In hot weather (×1.63) daily need rises to about 4,480 litres and 3 days to 13,450 litres, so a 16,000-litre tank is the safer choice if your summers reach 32 °C. Use the Farm Water Storage Calculator to factor in refill rate and pump flow.
✅ Sources & Review
Sources and review
The water rates and temperature factors on this page come from these references:
OMAFRA Factsheet 23-023: Water Requirements of Livestock — Ontario Ministry of Agriculture, Food and Rural Affairs (2023). Daily litres per head for dairy, beef, horses, swine, sheep and poultry; +50% for poultry above 30 °C.
The 25 L/head/day default for other animals, the ~10 L/day milking goat figure and the 15% purchase margin are planning values rather than published figures. Replace them with your own numbers when you have them.
Reviewed by John Mac, PE, Water Systems Specialist
Texas-licensed Professional Engineer with 13+ years in residential water storage and 180+ tank projects. John writes and reviews every calculator on this site.
