Home Well Water Storage Tank Sizing Calculator

Choosing the right size pressure tank keeps your well pump from short-cycling and extends its lifespan. Enter your household's peak water demand, your pump's flow rate, and how long you want the pump to rest between cycles to get a recommended drawdown and tank size.

Recommended Tank Drawdown Capacity
Drawdown needed per cycle (gal)
Peak demand buffer (gal)
Total recommended drawdown (gal)
Estimated total tank size (gal, ~33% drawdown ratio)

About this calculator

Calculate the ideal pressure/storage tank size for your well system based on household demand, pump flow rate, and desired run-time between pump cycles.

Frequently Asked Questions

What is 'drawdown' in a pressure tank?

Drawdown is the amount of water a tank can deliver between the pump's cut-in and cut-off pressure settings, typically about 1/3 of the tank's total volume.

Why does a bigger tank help my pump last longer?

A larger drawdown means fewer pump starts per hour, which reduces motor wear and heat buildup, extending pump life significantly.

What cycle time should I target?

Most manufacturers recommend at least 1 minute of continuous run time per cycle to avoid motor overheating; some pumps need longer.