Use the "Bucket Method" to calculate your well's Gallons Per Minute (GPM).
The volume of the bucket or container used for testing.
How many seconds it took to fill the container completely.
Flow Rate (GPM):–
Flow Rate (Liters/Min):–
24-Hour Yield Potential:–
function calculateWellFlow() {
// Get input values
var containerSize = parseFloat(document.getElementById('containerSize').value);
var fillTimeSeconds = parseFloat(document.getElementById('fillTime').value);
var resultsArea = document.getElementById('resultsArea');
var resultGPM = document.getElementById('resultGPM');
var resultLPM = document.getElementById('resultLPM');
var resultDaily = document.getElementById('resultDaily');
var flowStatus = document.getElementById('flowStatus');
// Validation
if (isNaN(containerSize) || containerSize <= 0) {
alert("Please enter a valid container size greater than 0.");
return;
}
if (isNaN(fillTimeSeconds) || fillTimeSeconds = 10) {
flowStatus.className = "status-box status-good";
flowStatus.innerHTML = "Excellent Flow Rate: Sufficient for large households and irrigation.";
} else if (gpm >= 6) {
flowStatus.className = "status-box status-good";
flowStatus.innerHTML = "Good Flow Rate: Sufficient for standard household usage.";
} else if (gpm >= 3) {
flowStatus.className = "status-box status-warning";
flowStatus.innerHTML = "Moderate/Low Flow: May require a storage tank or conservation during peak use.";
} else {
flowStatus.className = "status-box status-bad";
flowStatus.innerHTML = "Critical Low Flow: Water storage system highly recommended.";
}
}
How to Measure Your Well Water Flow Rate
Understanding your well's flow rate, typically measured in Gallons Per Minute (GPM), is crucial for maintaining a reliable water supply for your home. Whether you are buying a new home with a well, planning an irrigation system, or troubleshooting low pressure, knowing your specific numbers helps you make informed decisions.
The Importance of GPM (Gallons Per Minute)
The flow rate determines how many water fixtures you can run simultaneously. If your well produces 5 GPM but your shower, dishwasher, and washing machine combined require 8 GPM, you will experience a significant drop in pressure if all are used at once.
Standard Home Requirement: Most 3-4 bedroom homes require between 6 to 12 GPM to function comfortably.
Irrigation Needs: Lawn sprinklers can use anywhere from 3 to 10 GPM per zone, requiring a higher capacity well.
How to Perform the Bucket Test
The calculator above uses data from the "Bucket Test," which is the simplest way for a homeowner to estimate well yield. Follow these steps for an accurate reading:
Find a location: Use a faucet closest to the pressure tank (often a spigot on the tank itself or an outside faucet) to bypass internal house piping restrictions.
Get a container: Use a bucket of known volume. A standard 5-gallon bucket is most common. Ensure you know the exact volume.
Open the valve: Turn the water on full blast.
Time the fill: Use a stopwatch to measure exactly how many seconds it takes for the water to reach the rim of the bucket.
Calculate: Enter the bucket size and the time in seconds into the calculator above.
Interpreting Your Results
Once you have your GPM, compare it to your household needs:
10+ GPM: This is considered excellent. You likely do not need to worry about running multiple appliances simultaneously.
6 – 9 GPM: This is average and sufficient for most families, though you may notice pressure drops if irrigating the lawn while showering.
Under 5 GPM: This is considered low yield. While the well may produce enough water over a 24-hour period (Daily Yield), it cannot supply high instantaneous demand.
Solutions for Low Flow Wells
If your calculator result indicates a low flow rate, you are not necessarily out of water. The daily yield might still be high enough to support a family. In these cases, installing a water storage tank (cistern) or a larger pressure tank is the standard solution. This allows the well to fill the tank slowly over time, and a booster pump sends water to your fixtures at high pressure when needed.