Please enter valid positive numbers for volume and time.
Flow Rate per Hour:
0
Equivalent Flow Rate per Minute:
0
function calculateFlowRate() {
// Get input values
var volume = document.getElementById('volumeInput').value;
var volumeUnit = document.getElementById('volumeUnit').value;
var time = document.getElementById('timeInput').value;
var timeUnit = document.getElementById('timeUnit').value;
var errorDisplay = document.getElementById('errorDisplay');
var resultBox = document.getElementById('resultBox');
// Reset display
errorDisplay.style.display = 'none';
resultBox.style.display = 'none';
// Validation
if (volume === "" || time === "" || isNaN(volume) || isNaN(time)) {
errorDisplay.innerHTML = "Please enter valid numeric values.";
errorDisplay.style.display = 'block';
return;
}
volume = parseFloat(volume);
time = parseFloat(time);
if (time <= 0) {
errorDisplay.innerHTML = "Time duration must be greater than zero.";
errorDisplay.style.display = 'block';
return;
}
// Convert Time to Hours
var timeInHours = 0;
if (timeUnit === 'hours') {
timeInHours = time;
} else if (timeUnit === 'minutes') {
timeInHours = time / 60;
} else if (timeUnit === 'seconds') {
timeInHours = time / 3600;
}
// Calculate Rate per Hour
var ratePerHour = volume / timeInHours;
// Calculate Rate per Minute (for secondary display)
var ratePerMinute = ratePerHour / 60;
// Formatting numbers
var formattedHourly = ratePerHour % 1 !== 0 ? ratePerHour.toFixed(2) : ratePerHour;
var formattedMinute = ratePerMinute % 1 !== 0 ? ratePerMinute.toFixed(4) : ratePerMinute;
// Update UI
document.getElementById('hourlyResult').innerHTML = formattedHourly + " " + volumeUnit + " / hr";
document.getElementById('minuteResult').innerHTML = formattedMinute + " " + volumeUnit + " / min";
resultBox.style.display = 'block';
}
Understanding the Flow Rate per Hour Calculator
Whether you are working in plumbing, industrial fluid dynamics, or medical administration, calculating the flow rate is a fundamental necessity. The Flow Rate per Hour Calculator helps you determine exactly how much volume passes through a specific point over a period of one hour.
What is Flow Rate?
Volumetric flow rate is the measure of the volume of liquid that passes through a cross-sectional area per unit of time. While flow rate can be measured in seconds or minutes, calculating it "per hour" (GPH, LPH) is standard for pump sizing, irrigation systems, and heating systems.
The Flow Rate Formula
The basic formula for calculating flow rate ($Q$) is the change in volume ($V$) divided by the change in time ($t$).
Q = V / t
Where:
Q = Flow Rate (e.g., Gallons per Hour)
V = Total Volume (e.g., Gallons, Liters)
t = Time duration (Hours)
How to Calculate Flow Rate per Hour
To use this calculator effectively, or to do the math manually, follow these steps:
Identify the Volume: Determine the total amount of fluid moved. For example, a tank might fill with 150 liters.
Measure the Time: Record how long it took to move that volume. For instance, 45 minutes.
Convert Time to Hours: Since we want the rate per hour, convert minutes to hours.
45 minutes ÷ 60 = 0.75 hours.
Divide Volume by Time: 150 Liters ÷ 0.75 Hours = 200 Liters per Hour (LPH).
Common Unit Conversions
In different industries, you might encounter different units. Here is how they relate to the hourly calculation:
GPH (Gallons Per Hour): Common in US plumbing and pool pumps.
LPH (Liters Per Hour): Standard in scientific and European industrial contexts.
m³/h (Cubic Meters Per Hour): Used for large-scale water treatment or HVAC air flow.
mL/hr (Milliliters Per Hour): Extremely common in medical settings for IV infusion pumps.
Practical Example: Sump Pump Calculation
Imagine you have a sump pit that holds 20 gallons of water. During a storm, you notice the pit fills up and the pump empties it completely in 90 seconds. To find the flow rate of the incoming water: