Paddock Size Calculator
Size each break to the herd and the graze period, and see how many paddocks the rotation needs.
Your numbers
Paddock size for a 3.0-day graze period
7.1 acres per paddock
- Paddocks needed
- 13 paddocks
- Total acres in the rotation
- 92.2 acres
- Stock density
- 10,600 lb/acre
- A square paddock of this size is about 556 ft on a side, so the far corner is roughly 389 ft from a central water point (your limit is 800 ft).
- Convention: intake scales linearly with body weight, the same convention used in state extension AUE tables and across every Agrilot grazing tool. Energy-based intake models such as NASEM scale by metabolic weight instead, and will differ modestly for herds well above or below a 1,000 lb mature weight.
- Size paddocks by grazing days, not by acres — put fewer acres in the productive bottoms and more on the thin ground.
Show the math
- Herd daily intake60 head × 1,250 lb × 2.6% = 1,950 lb DM/day
- Forage needed per paddock1,950 lb/day × 3.0 days = 5,850 lb DM
- Forage harvested per acre1,500 lb DM/acre × 55% = 825 lb DM/acre
- Paddock size5,850 ÷ 825 = 7.09 acres
- Paddock count(35 days rest ÷ 3.0 days graze) + 1 = 13 paddocks
- Land in the rotation7.09 acres × 13 = 92 acres
Assumptions this calculator used
Nothing here is hidden. Change any figure you have better local data for.
2.6% reflects a lactating cow; use closer to 2.0% if the group is mostly dry cows on mature forage. Source: NASEM/NRC Nutrient Requirements of Beef Cattle, 8th rev. ed..
% of body weightBeyond this, cattle graze unevenly and camp near the tank. Source: USDA-NRCS prescribed grazing standard (Code 528).
ft
How to calculate paddock size
Paddock size is a demand-versus-supply problem for a fixed number of days. Work out what the herd eats in the graze period, divide by the forage an acre will actually hand over, and you have the acres. Paddock count is then a scheduling question driven entirely by the rest period you are trying to deliver.
Acres = (head × weight × intake % × graze days) ÷ (available lb DM/acre × utilization)
Paddocks = (rest days ÷ graze days) + 1
Worked example
Sixty head averaging 1,250 lb eat 1,950 lb of dry matter a day. Over a three-day break that is 5,850 lb. If the paddock offers 1,500 lb DM/acre above residual and cattle harvest 55% of it, each acre yields 825 lb — so the break is about 7.1 acres. To rest each paddock 35 days on a three-day move you need 13 paddocks, or about 92 acres in the rotation.
Common mistakes
- Building permanent fence first. Run the rotation on polywire for a season, find out where the cattle and water actually want to be, then build.
- Sizing every paddock the same. Equalize grazing days, not acres.
- Forgetting the +1 in paddock count. The herd occupies one paddock while the rest recover; leave it out and every paddock comes up short on rest.
- Ignoring walk-to-water. A perfectly sized paddock with water 2,000 ft away gets grazed hard near the tank and left standing at the back.
Paddock count vs rest period at common graze periods
Paddocks required to deliver a given rest period, including the one the herd is standing in. Read down your intended graze period and across to the rest you need in that season.
| Graze period | 21-day rest | 30-day rest | 45-day rest | 60-day rest | 90-day rest |
|---|---|---|---|---|---|
| Half a day | 43 | 61 | 91 | 121 | 181 |
| 1 day | 22 | 31 | 46 | 61 | 91 |
| 2 days | 12 | 16 | 24 | 31 | 46 |
| 3 days | 8 | 11 | 16 | 21 | 31 |
| 4 days | 7 | 9 | 13 | 16 | 24 |
| 5 days | 6 | 7 | 10 | 13 | 19 |
| 7 days | 4 | 6 | 8 | 10 | 14 |
| 10 days | 4 | 4 | 6 | 7 | 10 |
| 14 days | 3 | 4 | 5 | 6 | 8 |
Calculators to run next
- Pasture Rest Period CalculatorUse when regrowth is falling short and the rotation needs to slow down.
- Acreage CalculatorUse when you need the acreage of an odd-shaped field before any forage math.
- Stocking Rate CalculatorStart here when the question is how many cows the whole place will run for a season.
- Animal Unit Equivalent CalculatorUse when the herd is mixed, so one number stands in for every class on the place.
- Grazing Days CalculatorUse when the herd is already in the paddock and you need a move date.
- Forage Yield CalculatorRun this first — every other grazing number depends on pounds of dry matter per acre.
Guides that use this calculator
- Cattle Water Requirements and Sizing a Tank That Keeps UpDaily gallons per head is the easy part. Peak-hour demand is what empties the tank in August.
- Fencing a Rotational Grazing System Without Overbuilding ItLay the paddocks out around water first. Order the posts second. Most people do it the other way and pay for it.
- How Many Cows Per Acre: Working Out Stocking Rate HonestlyCows per acre is an output, not an input. Here is the dry matter arithmetic behind it, the utilization rate most people get wrong, and honest numbers by region.
Questions ranchers ask
How big should each paddock be?
Big enough to feed the herd for the graze period you intend, and no bigger. Acres per paddock equals herd daily intake times days in the paddock, divided by the available forage per acre. A one-day break for 60 pairs on good spring pasture is often only 2 to 4 acres, which surprises people used to 40-acre fields.
How many paddocks do I need?
Paddock count equals rest period divided by graze period, plus one. Thirty days of rest with a three-day graze period means eleven paddocks. If you want the same rest with a one-day move you need thirty-one, which is why most operations use temporary polywire inside permanent subdivisions rather than building all of it in barbed wire.
Is it better to have more, smaller paddocks?
Up to a point. More paddocks means shorter graze periods, longer rest, more uniform manure distribution, and higher utilization. The returns flatten out somewhere past 20 to 30 paddocks, and every extra subdivision adds water infrastructure and daily labor. Most well-run cow-calf operations land between 8 and 24 paddocks.
Do all paddocks have to be the same size?
No, and they rarely should be. Match paddock size to productivity — a fertile bottom paddock will feed the herd for the same number of days at half the acres of a thin ridge. Equal grazing days, not equal acres, is the goal.
Where does water fit into paddock layout?
Water is the constraint that decides the layout, not the fence. Cattle should not walk more than about 800 feet to water in intensive systems, or 1,200 to 1,600 feet in extensive ones, before grazing distribution deteriorates. Lay out water points first, then draw fences around them — usually a wagon-wheel or a central lane design.
Should I strip graze instead of building paddocks?
Strip grazing with a single polywire moved daily is the cheapest way to get most of the benefit, especially on stockpiled forage or annuals. It needs a back fence to stop regrazing, and it needs water access in every strip. Many producers strip graze inside larger permanent paddocks.
What stock density should I aim for?
Conventional rotational grazing runs 15,000 to 50,000 lb of live weight per acre at any moment. Mob grazing pushes 100,000 lb or more per acre for very short periods. Higher density improves utilization and trampling of litter but demands daily or twice-daily moves and abundant water.
How do I handle regrowth if I have too few paddocks?
Slow the rotation, take some paddocks out for hay in the spring flush, or add temporary subdivisions. With fewer than about six paddocks, the rest period simply cannot get long enough in midsummer, and utilization drops toward continuous-grazing levels.
Subdividing means you can carry more cattle
Going from continuous grazing to a planned rotation commonly lifts utilization from 30% to 50% — the same ground, materially more grass harvested. When you are ready to stock up to it, Agrilot lists registered Angus females with breeding records and an independent condition report on every lot.