How do you calculate the number of paddocks needed?

The number of paddocks equals the rest period divided by the grazing period, plus one. The plus one ensures the herd has a fresh paddock to move into while every other paddock completes its rest. For a 30-day rest and 3-day grazing, you need 30 / 3 + 1 = 11 paddocks.

What is a rest period and why does it matter?

The rest period is how long a paddock recovers before being grazed again. It must be long enough for plants to regrow leaf area and rebuild root reserves. Too short and the pasture is overgrazed; too long and forage becomes mature and low quality. It varies with season and growth rate.

How long should the grazing period be?

Shorter is generally better for plant health. Keeping animals on a paddock one to three days prevents them from regrazing fresh regrowth before they move on. Longer grazing periods need more rest to compensate and can stress the most palatable plants.

How do animal units relate to stocking?

An animal unit (AU) is a standard 1,000-pound animal eating about 26 pounds of dry forage per day, roughly 3 percent of body weight. Converting your herd to animal-unit equivalents lets you compare forage demand against available pasture regardless of species or class.

What is the rotation cycle length?

The cycle length is how long it takes the herd to graze every paddock once and return to the first. It approximately equals the rest period plus one grazing period. Watching the cycle against pasture growth tells you when to speed up or slow down the rotation.

Paddock Rotation Calculator

A productive grazing rotation balances how long animals stay against how long pastures rest. This calculator converts your target rest period and grazing period into the number of paddocks you need and the length of the rotation cycle, with an optional stocking check from herd size and available forage.

How it works

The paddock count comes directly from the rest-to-graze ratio:

paddocks      = (rest period / grazing period) + 1
cycle length  ≈ rest period + grazing period
forage demand = animal units × 26 lb/day × grazing period   (optional)

The plus-one guarantees a fresh paddock is always ready while the rest of the cells finish recovering. The optional forage demand uses the standard animal-unit intake of about 26 pounds of dry matter per day.

Example and tips

For a 30-day rest with a 3-day grazing period, you need 30 / 3 + 1 = 11 paddocks and a rotation cycle of about 33 days. A 40-AU herd would eat roughly 40 × 26 × 3 = 3,120 pounds of dry forage per 3-day move. Shorten the rest period and add paddocks during the spring flush when grass grows fast, then lengthen rest and slow the rotation as growth slumps in summer. Always graze to a residual height that lets plants regrow quickly.