Water demand calculator

Water demand calculator

The calculator below uses values consistent with the IBO catalog (page with tables flows, pressures and demand). The values are there averaged, because different devices and installations they can operate in a wide range of flows depending on pressure, pipe diameter, nozzle and fittings design.

The calculator allows you to estimate temporary (simultaneous) water demand, and also indicative daily consumption for animals based on industry standards and IBO tables.

1. Water intake points - average values

The flows below come from tables from the IBO catalog. These are values estimated for standard operating conditions (typical pressures 1.4–2.1 bar). Actual flow may vary depending on installation, condition of fittings and network pressure.

Collection point Typical flow (l/min) Quantity
Shower (1.4 bar)
Typically 8-10 L/min - an average of 9 L/min was used. 		9
Compact toilet
One filling is usually 6-9 l - 8 l/min was assumed as a typical instantaneous load. 		8
Small lawn sprinkler
Typically 15-20 L/min - 17.5 L/min was 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 wear and tear of your washing machine should be checked on nameplate or in the manual. Washing machines can draw water in bursts, and the instantaneous flow depends on solenoid valves.
Own collection point
Any hydraulic device.
Total instantaneous demand:
0 l/min
0 m³/h
Conversion rate: 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. Applied average values ~42.5 l/day for most species, because actual consumption depends on:

  • air temperature,
  • animal weight,
  • growth period,
  • watering system (bowls, pressure drinkers, teats),
  • type of feed.
Animal l/day/pcs. Quantity
Cattle 42.5
Cash cows 42.5
Sheep 42.5
Pigs 42.5
Horses 42.5
Daily water consumption: 0 l/day
0 m³/day
3. Dependence of pressure on altitude above sea level

According to the tables from the IBO catalog and hydraulic standards: atmospheric pressure drops by approximately 0.01 bar for every 100 m of height.

This means that the higher the installation, the lower the pressure available at the entrance to the pump or hydrophore.

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

A self-priming pump at sea level can, under ideal conditions, suck water from 8–9 m. As the altitude increases, the available pressure decreases → the suction height decreases.

Dependency: 0.1 m drop / 100 m height.

Height (m above sea level) Suction capacity drop (m) Estimated max. suction lift (m)
0.00 m 8.50 m
Explanation: Maximum suction assumed: 8.5 m. Every 1000 m of height = approx. 1 m less suction.
Reference data from the IBO catalog - full table

Typical flows:

  • 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