Well Volume Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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The Well Volume Calculator answers a narrow everyday question without hiding the arithmetic. It is built to estimate the water volume in a cylindrical well from inside diameter and water-column depth. For the Well Volume Calculator, that makes the result easy to sanity-check because you can change one assumption and see immediately what moved.

What this calculator does

The primary result is “Water volume in well” and is displayed in US gal. Supporting values on the page include Liters, Cubic meters. In practical terms, the Well Volume Calculator is meant to estimate the water volume in a cylindrical well from inside diameter and water-column depth. The Well Volume Calculator does not infer or add inputs that are absent from its visible form.

How to use it

Enter Well inside diameter and Water column depth. For the Well Volume Calculator, check the selected unit beside every measured quantity. When comparing Well Volume Calculator scenarios, change one field at a time so the source of the difference stays obvious.

How the calculation works

For the Well Volume Calculator, the water column is treated as a cylinder. Volume = π×(inside diameter/2)²×water depth after unit normalization; the page then converts cubic meters to liters and U.S. gallons.

Example

A 6-inch inside diameter is 0.1524 m, so a 100-foot water column gives about 0.556 m³ of cylindrical water volume. The page converts that to roughly 556 L or 146.9 U.S. gallons.

How to interpret the result

The gallon/liter result is the static cylindrical volume represented by the entered water depth. It can help with storage or treatment planning, but it does not tell you how fast the well can sustainably deliver water.

Limitations and notes

For the Well Volume Calculator, the cylinder model assumes a constant inside diameter and uses the entered water-column depth, not total drilled depth. Casing geometry, sediment, pump placement, recharge rate, drawdown, and usable storage are outside the calculation.