Wells & water/ CALCULATOR

Gravity-tank water pressure at an outlet

Estimate the pressure available from the lowest tank water level after elevation and entered flow losses.

Lowest operating water-level elevationmUse the water surface at the lowest level intended for normal operation and one common project datum.

Outlet elevationmUse the same datum and the elevation of the pressure point being checked.

Pipe and equipment losses at design flowmEnter friction and equipment loss as metres of water head at the intended flow.

Required pressure at outletbarUse the applicable fixture or equipment requirement at the design flow.

Static elevation head

10.00 m

Available head after entered losses

8.00 m

Estimated available pressure

0.78 bar

Estimated available pressure

11.36 psi

Pressure margin above requirement

-0.22 bar

Interpretation:After the entered flow losses, available pressure is about 0.22 bar below the requirement. Raise the usable water level, reduce verified losses or provide suitable pressure boosting.

Water density 998 kg/m³ and gravity 9.80665 m/s². The entered loss must represent the selected flow and route. Tank outlet loss, changing water level, air locks, pipe sizing, valves, treatment equipment, backflow protection, minimum service pressure and local plumbing rules are not determined automatically. Negative available pressure means gravity cannot overcome the entered losses at that condition.

FROM ESTIMATE TO ACTION

Use the result, not just the number.

Verify the inputs

Measure or document each input. If a value is only an estimate, record its source and test a conservative alternative.

Keep the calculation traceable

Save the input link or copied result together with the date, units and assumptions. A number without its inputs cannot be checked later.

Confirm the decision

Compare the estimate with the related guide, current product data and requirements that apply at your location before buying or building.

Inputs to verify

Lowest operating water-level elevation (m): Use the water surface at the lowest level intended for normal operation and one common project datum.
Outlet elevation (m): Use the same datum and the elevation of the pressure point being checked.
Pipe and equipment losses at design flow (m): Enter friction and equipment loss as metres of water head at the intended flow.
Required pressure at outlet (bar): Use the applicable fixture or equipment requirement at the design flow.

Continue your calculation

Wells & water

Water pressure to head

Convert water pressure into metres of head and psi using a stated density.