A well that met your household's needs ten years ago can quietly fall behind it — more people, more irrigation, a dropping water table. This calculator estimates your daily demand, your peak-hour demand, and checks both against your well's measured flow rate so you can spot a capacity problem before it becomes a dry tap.
How to read your numbers
Daily totals matter less than peak demand — the morning window when two showers, a dishwasher, and a washing machine all run at once. A household's peak draw is commonly estimated at 5–7 gallons per minute. If your well produces less than that, a properly sized pressure tank or storage tank bridges the gap by accumulating water during quiet hours.
Don't know your well's flow rate?
You can measure it yourself in about an hour: run an outside spigot into a 5-gallon bucket, time how long it takes to fill, and repeat every 10 minutes for an hour (the first measurements draw from the pressure tank, not the well). The stabilized number is your working flow rate. For lending or real-estate purposes you'll need a licensed well contractor's test, typically $150–$400.
Frequently Asked Questions
How many gallons per minute is a good well?
For a typical single-family home, 5 gallons per minute (GPM) is the widely used benchmark for adequate supply, and many lenders (FHA/VA) look for 3–5 GPM minimum. Wells producing 1–3 GPM can still work with a storage tank to buffer peak demand.
How much water does a household use per day on a well?
Plan on 60–80 gallons per person per day for indoor use. A family of four typically draws 250–320 gallons daily before any irrigation or livestock. Outdoor watering can easily double that in summer.
What happens if my well cannot keep up with demand?
Symptoms include pressure drops during simultaneous use, air sputtering from faucets, and the pump running dry. Solutions in rising order of cost: low-flow fixtures and staggered usage, a larger pressure/storage tank, hydrofracturing the existing well, or drilling deeper or a second well.
Does a low-yield well hurt home resale value?
It can. Many buyers’ lenders require a flow test, and results under 3 GPM without a storage system can complicate financing. If you’re selling a home with a low-yield well, adding storage capacity before listing is often cheaper than the price reduction buyers will demand.