Water Intake Calculator

Water demand calculator

The calculator below uses values consistent with the IBO catalog (the page with tables flow rates, pressures, and demand). The values are averaged because different devices and installations may operate across a wide range of flow rates depending on pressure, pipe diameter, nozzles, and the design of the fittings.

The calculator estimates the instantaneous (simultaneous) water demand, as well as the approximate daily consumption for animals based on industry standards and IBO tables.

1. Water outlets – averaged values

The following flow rates are taken from tables in the IBO catalog. These are estimated values for standard operating conditions (typical pressures of 1.4–2.1 bar). The actual flow rate may vary depending on the installation, the condition of the fittings and the pressure in the network.

Water outlet Typical flow rate (l/min) Quantity
Shower (1.4 bar)
Typically 8–10 l/min — averaged value of 9 l/min used. 		9
Compact toilet
One fill is usually 6–9 l — 8 l/min adopted as the typical instantaneous load. 		8
Small lawn sprinkler
Typically 15–20 l/min — averaged value of 17.5 l/min used. 		17.5
1/2" tap
Typical 12–18 l/min — 15 l/min used. 		15
3/4" hose + 1/4" nozzle
40–50 l/min — 45 l/min used. 		45
1" hose + 3/8" nozzle
70–90 l/min — 80 l/min used. 		80
Washing machine
The washing machine's consumption should be checked on the nameplate or in the manual. Washing machines may draw water intermittently, and the instantaneous flow rate depends on the solenoid valves.
Individual water outlet
Any hydraulic device.
Total instantaneous demand:
0 l/min
0 m³/h
Conversion: 1 m³/h = 16.7 l/min (according to the IBO table).
2. Daily water requirement for animals

Daily values for animals come from the IBO table. Average values of ~42.5 l/day were used for most species because actual consumption depends on:

  • air temperature,
  • animal weight,
  • growth period,
  • watering system (bowls, pressure drinkers, nipples),
  • type of feed.
Animal l/day/animal Quantity
Cattle 42.5
Dairy cows 42.5
Sheep 42.5
Pigs 42.5
Horses 42.5
Daily water consumption: 0 l/day
0 m³/day
3. Relationship between pressure and elevation above sea level

According to the tables in the IBO catalog and hydraulic standards: atmospheric pressure drops by approx. 0.01 bar for every 100 m of elevation.

This means that the higher the installation is located, the lower the pressure available at the pump inlet or pressure tank.

Elevation (m above sea level) Pressure reduction (bar)
0.00 bar
Explanation: At 800 m above sea level, the pressure drop is approx. 0.08 bar.
4. Decrease in pump suction capacity at elevation above sea level

At sea level, a self-priming pump can draw water from 8–9 m. As elevation increases, the available pressure decreases → suction height decreases.

Relationship: 0.1 m decrease / 100 m of elevation.

Elevation (m above sea level) Decrease in suction capacity (m) Estimated maximum suction height (m)
0.00 m 8.50 m
Explanation: Maximum suction assumed: 8,5 m. Every 1,000 m of elevation = approx. 1 m less suction.
Reference data from the IBO catalog – complete table

Typical flow rates:

  • Shower: 8–10 l/min
  • Sprinkler: 15–20 l/min
  • 1/2" tap: 12–18 l/min
  • Garden hoses: 40–90 l/min
Units:
  • 0.17 l/s = 10 l/min = 0.60 m³/h
  • 0.28 l/s = 16.7 l/min = 1 m³/h
  • 1 l/s = 60 l/min = 3.60 m³/h