Rotational Grazing Calculator

Days grazing available, daily strip area and paddocks needed for your rotation.

Want to track live paddock covers?

The Grass Wedge Planner saves your paddock data and builds a live wedge chart.

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Livestock Type

Livestock

Herd Size(head)

Avg Liveweight(kg)

DM Intake (% liveweight)

= 18.0 kg/head/day

Paddock

Paddock Size

Target Residual(kg DM/ha)

Leave behind this DM cover when moving on

Pre-grazing DM Cover

DM cover: ? × 125 + 640

—

Rotation Target

Target Rest Period(days)

Days between grazings — typically 21–28 days in summer

Results

Usable DM—

Daily demand—

Days grazing—

Daily strip—

Strip (m²)—

Paddocks needed—

Rotation length—

Total area needed—

Based on uniform grass cover — adjust for variable sward.

Sward Height Formula (AHDB / Compressed Plate Meter)

The sward height method uses the standard UK calibration for a compressed sward plate meter reading:

DM cover (kg/ha) = sward height (cm) × 125 + 640

Source: AHDB Dairy / Beef & Lamb grassland management guidelines. Applies to perennial ryegrass-dominant swards. Sward type and season can affect accuracy — use a plate meter for best results.

Recommended Tools & Equipment

Everything you need for a successful rotational grazing system.

Plate Meter / Sward Stick

Compressed sward plate meter for accurate pre-grazing and residual DM readings.

Electric Fence Reel

Break fencing reel for moving daily allocations in rotational grazing systems.

Solar Electric Fence Energizer

Solar-powered energizer for paddock sub-division and strip grazing.

Piket / Temporary Fence Posts

Lightweight piket posts for laying out daily strips and paddock breaks.

Rotational Grazing Handbook

Practical guide to mob grazing, rest periods and grass management for UK farms.

Livestock Weighing Tape

Estimate liveweight by heart girth measurement — essential for DM demand calculations.

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Reference Data (AHDB)

Typical values to guide your inputs — adjust to your farm and season.

Livestock	Pre-grazing DM	Residual target	DM intake	Spring rest	Summer rest	Autumn rest
Dairy Cow	2,800–3,200 kg/ha	1,500–1,800 kg/ha	3.0%	14–18 days	21–28 days	28–35 days
Beef Cattle	2,500–3,000 kg/ha	1,200–1,500 kg/ha	2.5%	18–21 days	25–30 days	30–35 days
Sheep	2,000–2,500 kg/ha	800–1,200 kg/ha	2.5%	14–18 days	21–28 days	28–35 days

DM intake % is approximate for grazing conditions at maintenance + moderate production. Dairy cows in early lactation may exceed 3.5%. Longer rest periods promote better grass recovery — shorten rest in spring flush, extend in summer drought.