Short answerPlan on about 20 gallons a head a day for beef cattle in hot weather (NDSU Extension), pump to a tank holding at least three days of demand, and size the array for the month you graze with the least sun. Fifty cows need about 1,000 gallons a day, roughly 3.3 gpm over 5 sun hours.
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Key takeaways
- Size for hot weather: a beef animal can drink about 20 gallons a day at 90F.
- Pump to a storage tank and feed troughs by gravity through a float valve.
- A grazing-season system can be far smaller than a year-round one in northern states.
How much they drink
Water intake climbs steeply with temperature, so size for the hottest weeks. The figures below are from North Dakota State University Extension's Livestock Water Requirements (AS1763, revised February 2026).
| Animal | Gallons per head per day | Conditions |
|---|---|---|
| Growing cattle, 400 lb | 4.0 to 9.5 | 40F to 90F |
| Finishing cattle, 1,000 lb | up to 20.6 | 90F |
| Milking dairy cow, 80 lb milk/day | 30 to 36 | |
| Dry dairy cow | 9 to 13 | |
| Horse, idle, 1,100 lb | 8.2 to 12.7 | 68F to 86F |
| Horse, moderate work, 1,100 lb | 21.7 | 95F |
| Lactating ewe | 2 to 3 | |
| Finishing pig, 100 to 250 lb | 2 to 3 | |
| Lactating sow | 5 to 8 |
The calculator uses 20 gallons for a beef animal in hot weather, 35 for a milking cow, 15 for a horse and 2.5 for a sheep or goat. NDSU does not list goats; we use the ewe figure.
Run your own numbers. The sizing calculator shows every step, for your state, lift and pipe.
Open the calculatorLayout that works
- Pump to a storage tank holding at least three days of peak demand, ideally on high ground.
- Feed troughs by gravity through a float valve, so a trough stays small, fresh and cool.
- Put a float switch in the storage tank to stop the pump when it is full.
- Protect the wellhead and panels with fencing: cattle rub on anything.
- Harden the ground around troughs with gravel or geotextile; it becomes the muddiest spot on the place.
Grazing season vs year-round
Many stock wells only need to run from spring to autumn. Sizing for April to October instead of December can halve the array in northern states. Our state pages show the difference month by month. For year-round water, size for the darkest month, store more, and read winterizing.
Off-stream water and cost share
Moving cattle off a creek onto a trough is one of the most common conservation practices NRCS cost-shares through EQIP, typically as a pumping plant (practice 533) with a watering facility and pipeline. See USDA grants for solar pumps.
VEVOR 12V DC 120W submersible deep well pump
Low-volume wells: a cabin, a garden or a few head of stock. The deepest submersion rating of the three.
- Voltage
- 12V DC (12 to 14.8V)
- Rated power
- 120 W
- Max flow (zero head)
- 3.2 gpm
- Max head (zero flow)
- 230 ft
- Max submersion
- 98.4 ft
- Outlet
- 1/2 in
- In the box
- Pump only: no panel, controller or pipe
VEVOR 24V DC 277W submersible deep well pump
Stock water and small irrigation where the water level is within about 100 ft.
- Voltage
- 24 to 42V DC (36V rated)
- Rated power
- 277 W
- Max flow (zero head)
- 9.25 gpm
- Rated point
- 5.28 gpm at 84 ft
- Max head (zero flow)
- 272 ft
- Max submersion
- 65.6 ft
- Outlet / cable
- 1 in / 33 ft
- In the box
- Pump only
VEVOR 48V DC 369W submersible deep well pump
Deeper lifts at modest flow. Wants two 36V-class panels in series to reach its voltage.
- Voltage
- 48 to 82V DC (72V rated)
- Rated power
- 369 W
- Max flow (zero head)
- 8.4 gpm
- Rated point
- 1.77 gpm at 167 ft
- Max head (zero flow)
- 273 ft
- Max submersion
- 65.6 ft
- Outlet / cable
- 1 in / 33 ft
- In the box
- Pump only
We have not tested these products; specifications are the merchant's own. Affiliate disclosure.
Questions
- How big a solar pump do I need for 50 head of cattle?
- At 20 gallons a head in hot weather that is 1,000 gallons a day. With 5 sun hours, the pump must hold 3.3 gpm at your total dynamic head. At 100 ft of head and 35% efficiency that is about 180 W at the pump, so roughly 240 W of panels before margin, plus a 3,000 gallon tank.
Twenty beef cattle on a well, year-round, as a starting point you can edit.