.flow-calc-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
max-width: 600px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 12px;
background-color: #ffffff;
box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}
.flow-calc-header {
text-align: center;
margin-bottom: 25px;
}
.flow-calc-header h2 {
color: #1a73e8;
margin: 0;
font-size: 24px;
}
.flow-calc-field {
margin-bottom: 20px;
}
.flow-calc-field label {
display: block;
font-weight: 600;
margin-bottom: 8px;
color: #333;
}
.flow-calc-field input, .flow-calc-field select {
width: 100%;
padding: 12px;
border: 1px solid #ccc;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box;
}
.flow-calc-btn {
width: 100%;
padding: 15px;
background-color: #1a73e8;
color: white;
border: none;
border-radius: 6px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.2s;
}
.flow-calc-btn:hover {
background-color: #1557b0;
}
.flow-calc-result {
margin-top: 25px;
padding: 20px;
background-color: #f8f9fa;
border-radius: 8px;
display: none;
}
.flow-calc-result h3 {
margin-top: 0;
color: #333;
font-size: 20px;
border-bottom: 2px solid #1a73e8;
padding-bottom: 10px;
}
.res-val {
font-size: 28px;
font-weight: bold;
color: #1a73e8;
}
.status-box {
margin-top: 10px;
padding: 10px;
border-radius: 4px;
font-weight: 500;
}
.flow-article {
max-width: 800px;
margin: 40px auto;
line-height: 1.6;
color: #444;
}
.flow-article h2 { color: #222; margin-top: 30px; }
.flow-article table { width: 100%; border-collapse: collapse; margin: 20px 0; }
.flow-article table th, .flow-article table td { border: 1px solid #ddd; padding: 12px; text-align: left; }
.flow-article table th { background-color: #f2f2f2; }
Container Volume
Unit of Measure
Gallons
Liters
Ounces (US)
Cups
Time to Fill (Seconds)
Calculate Flow Rate
Results
Flow Rate: 0.00 GPM
Metric Rate: 0.00 LPM
Understanding Faucet Flow Rates
Flow rate is the volume of water that passes through your faucet aerator per minute. It is typically measured in Gallons Per Minute (GPM) or Liters Per Minute (LPM) . Monitoring this is essential for water conservation and reducing utility bills.
How the 1-2-Freeze Method Works
The "1-2-Freeze" or timed-fill method is the most accurate way to test your plumbing fixtures at home without professional equipment. Follow these steps:
Prepare: Grab a measuring cup or a marked jug (a 1-gallon milk jug is perfect).Position: Place the container under the faucet.Start: Turn the faucet to full blast and start your stopwatch simultaneously.Freeze/Stop: Stop the timer the exact moment the water reaches your chosen volume mark.Calculate: Input your container size and the seconds recorded into the calculator above.
Standard Flow Rate Benchmarks
Fixture Type
Standard Flow (Old)
WaterSense High Efficiency
Bathroom Faucet
2.2 GPM
1.5 GPM or less
Kitchen Faucet
2.2 GPM
1.8 GPM or less
Showerhead
2.5 GPM
2.0 GPM or less
Example Calculation
If you fill a 1-quart (32 oz) container in 10 seconds , what is your GPM?
1 Quart = 0.25 Gallons
Calculation: (0.25 gallons / 10 seconds) × 60 seconds = 1.5 GPM
This fixture would meet the EPA WaterSense criteria for a bathroom sink!
function calculateFlowRate() {
var volume = parseFloat(document.getElementById('containerVolume').value);
var unit = document.getElementById('volumeUnit').value;
var seconds = parseFloat(document.getElementById('fillSeconds').value);
var resultDiv = document.getElementById('flowResult');
var gpmSpan = document.getElementById('gpmResult');
var lpmSpan = document.getElementById('lpmResult');
var statusDiv = document.getElementById('efficiencyStatus');
if (isNaN(volume) || isNaN(seconds) || seconds <= 0 || volume <= 0) {
alert("Please enter valid positive numbers for volume and time.");
return;
}
var volumeInGallons = 0;
// Convert all inputs to Gallons
if (unit === 'gallons') {
volumeInGallons = volume;
} else if (unit === 'liters') {
volumeInGallons = volume * 0.264172;
} else if (unit === 'ounces') {
volumeInGallons = volume / 128;
} else if (unit === 'cups') {
volumeInGallons = volume / 16;
}
// Calculate GPM: (Gallons / Seconds) * 60
var gpm = (volumeInGallons / seconds) * 60;
var lpm = gpm * 3.78541;
// Display Results
gpmSpan.innerText = gpm.toFixed(2);
lpmSpan.innerText = lpm.toFixed(2);
resultDiv.style.display = 'block';
// Efficiency Rating Logic
if (gpm <= 1.5) {
statusDiv.innerHTML = "Efficiency Rating: High Efficiency (WaterSense Compliant)";
statusDiv.style.backgroundColor = "#e6fffa";
statusDiv.style.color = "#006b5f";
statusDiv.style.border = "1px solid #b2f5ea";
} else if (gpm <= 2.2) {
statusDiv.innerHTML = "Efficiency Rating: Standard Flow";
statusDiv.style.backgroundColor = "#fffbe6";
statusDiv.style.color = "#856404";
statusDiv.style.border = "1px solid #ffeeba";
} else {
statusDiv.innerHTML = "Efficiency Rating: High Flow (Consider an Aerator)";
statusDiv.style.backgroundColor = "#fff5f5";
statusDiv.style.color = "#c53030";
statusDiv.style.border = "1px solid #feb2b2";
}
}