AgricultureID

Calculator · water

Irrigation volume calculator

Net irrigation volume from a target depth and area, and gross volume from an application efficiency.

Required

Required

Leave blank for net volume only.

Result

Enter values to see a result.

Formula & assumptions

Net irrigation volume

formula v1.0.0 · calc v1 · reviewed 2026-07-12

net_volume_m³ = depth_mm × area_ha × 10

Applies to: Applying a target net depth of water to a field area.

Assumptions

  • 1 mm of water depth over 1 ha equals 10 m³.

Limitations

  • Net depth is the water required at the crop, before application losses.

Sources: FAO Land and Water Division (opens in a new tab)

Gross irrigation volume from efficiency

formula v1.0.0 · calc v1 · reviewed 2026-07-12

gross_volume = net_volume ÷ (application_efficiency% ÷ 100)

Applies to: Estimating water to supply given a system efficiency.

Assumptions

  • Application efficiency accounts for conveyance and application losses.

Limitations

  • Efficiency is system- and management-specific; a planning estimate only.

Sources: FAO Land and Water Division (opens in a new tab)

About this tool

  • Does not recommend a depth by crop. Net depth is the requirement at the crop; gross adds losses. A planning estimate, not a scheduling prescription.

Educational reference — not a prescription

  • These calculators are for education and reference. The quality of any result depends entirely on the accuracy of the values you enter.
  • Local agronomic conditions, legal requirements, product labels, and professional advice may override a general calculation.
  • Results are not pesticide, fertilizer, irrigation, or veterinary prescriptions, and are not a substitute for advice from a qualified agronomist or your local extension service.