Flow Rate Calculator Volume Time

by
Flow Rate Calculator (Volume / Time) .frc-container { max-width: 800px; margin: 0 auto; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; color: #333; line-height: 1.6; } .frc-calculator-card { background: #f9fbfd; border: 1px solid #e1e4e8; border-radius: 8px; padding: 30px; margin-bottom: 40px; box-shadow: 0 4px 6px rgba(0,0,0,0.05); } .frc-input-group { margin-bottom: 20px; } .frc-input-group label { display: block; font-weight: 600; margin-bottom: 8px; color: #2c3e50; } .frc-row { display: flex; gap: 15px; flex-wrap: wrap; } .frc-col { flex: 1; min-width: 200px; } .frc-input, .frc-select { width: 100%; padding: 12px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; box-sizing: border-box; } .frc-input:focus, .frc-select:focus { border-color: #007bff; outline: none; } .frc-btn { background-color: #007bff; color: white; border: none; padding: 15px 30px; font-size: 18px; font-weight: bold; border-radius: 4px; cursor: pointer; width: 100%; transition: background-color 0.2s; } .frc-btn:hover { background-color: #0056b3; } .frc-result-box { margin-top: 25px; padding: 20px; background-color: #e8f4fd; border-left: 5px solid #007bff; border-radius: 4px; display: none; } .frc-result-title { font-size: 14px; text-transform: uppercase; color: #555; letter-spacing: 1px; margin-bottom: 5px; } .frc-result-value { font-size: 32px; font-weight: 700; color: #007bff; } .frc-content { margin-top: 50px; padding-top: 20px; border-top: 1px solid #eee; } .frc-content h2 { color: #2c3e50; margin-top: 30px; } .frc-content h3 { color: #34495e; margin-top: 20px; } .frc-content ul { margin-bottom: 20px; } .frc-content li { margin-bottom: 10px; } .frc-formula { background: #eee; padding: 15px; font-family: monospace; text-align: center; font-size: 1.2em; margin: 20px 0; border-radius: 4px; } .frc-table { width: 100%; border-collapse: collapse; margin: 20px 0; } .frc-table th, .frc-table td { border: 1px solid #ddd; padding: 12px; text-align: left; } .frc-table th { background-color: #f2f2f2; }

Flow Rate Calculator

Calculate volumetric flow rate based on volume and time.

Liters (L) US Gallons (gal) UK Gallons (gal) Cubic Meters (m³) Cubic Feet (ft³) Milliliters (mL)
Seconds (s) Minutes (min) Hours (hr)
Liters per minute (L/min) Liters per second (L/s) Liters per hour (L/hr) US Gallons per minute (GPM) US Gallons per hour (GPH) Cubic Meters per second (m³/s) Cubic Meters per minute (m³/min) Cubic Meters per hour (m³/hr) Cubic Feet per second (cfs) Cubic Feet per minute (cfm)
Calculated Flow Rate
0

How to Calculate Flow Rate

The volumetric flow rate represents the volume of fluid that passes through a given cross-sectional area per unit of time. Understanding how to calculate this metric is essential in fields ranging from civil engineering and plumbing to medicine and chemical processing.

The Flow Rate Formula

The fundamental equation for volumetric flow rate is simple division. It determines how much space (volume) is filled or emptied over a specific duration.

Q = V / t

Where:

  • Q = Volumetric Flow Rate
  • V = Volume of the fluid (e.g., Liters, Gallons, m³)
  • t = Time elapsed (e.g., Seconds, Minutes, Hours)

Example Calculation

Imagine you need to fill a swimming pool that has a volume of 10,000 Gallons. You turn on the hose and measure that it takes 5 hours to fill completely. To find the flow rate of the hose:

  1. Identify Volume (V): 10,000 Gallons
  2. Identify Time (t): 5 Hours
  3. Apply Formula: Q = 10,000 / 5
  4. Result: 2,000 Gallons per Hour (GPH)

Common Units of Measurement

Flow rate units depend entirely on the application. Here are standardized units for different industries:

Industry/Application Common Units Typical Usage
Plumbing & Hydraulics GPM (Gallons per Minute), L/min Showerheads, faucets, pumps
Industrial Water Treatment m³/hr (Cubic meters per hour) Large scale filtration systems
HVAC CFM (Cubic Feet per Minute) Air flow in ducts and vents
Environmental Engineering cfs (Cubic Feet per Second) River flow, open channel flow
Medical mL/hr (Milliliters per hour) IV drip rates, infusion pumps

Factors Affecting Flow Rate

While this calculator determines flow based on volume and time, in physical systems, the flow rate is determined by:

  • Pipe Diameter: Larger pipes allow more fluid to pass through at lower velocities.
  • Pressure Differential: Higher pressure differences drive fluids faster.
  • Viscosity: Thicker fluids (like oil) flow slower than thinner fluids (like water) under the same force.
  • Friction: Roughness inside pipes creates resistance that reduces flow.
function calculateFlow() { // 1. Get Input Values var vAmount = parseFloat(document.getElementById("volumeAmount").value); var vUnit = document.getElementById("volumeUnit").value; var tAmount = parseFloat(document.getElementById("timeAmount").value); var tUnit = document.getElementById("timeUnit").value; var targetUnit = document.getElementById("targetUnit").value; // 2. Validation if (isNaN(vAmount) || isNaN(tAmount)) { alert("Please enter valid numbers for Volume and Time."); return; } if (tAmount <= 0) { alert("Time duration must be greater than zero."); return; } // 3. Conversion to Base Units // Base Volume = Liters (L) // Base Time = Minutes (min) var volumeInLiters = 0; // Convert input volume to Liters switch(vUnit) { case "liters": volumeInLiters = vAmount; break; case "gallons_us": volumeInLiters = vAmount * 3.78541; break; case "gallons_uk": volumeInLiters = vAmount * 4.54609; break; case "cubic_meters": volumeInLiters = vAmount * 1000; break; case "cubic_feet": volumeInLiters = vAmount * 28.3168; break; case "milliliters": volumeInLiters = vAmount / 1000; break; } var timeInMinutes = 0; // Convert input time to Minutes switch(tUnit) { case "seconds": timeInMinutes = tAmount / 60; break; case "minutes": timeInMinutes = tAmount; break; case "hours": timeInMinutes = tAmount * 60; break; } // 4. Calculate Base Flow Rate (Liters per Minute) var baseFlowRate = volumeInLiters / timeInMinutes; // 5. Convert Base Flow Rate to Target Unit var finalResult = 0; var unitLabel = ""; switch(targetUnit) { case "L_min": finalResult = baseFlowRate; unitLabel = "Liters / min"; break; case "L_sec": finalResult = baseFlowRate / 60; unitLabel = "Liters / sec"; break; case "L_hr": finalResult = baseFlowRate * 60; unitLabel = "Liters / hour"; break; case "gal_min": finalResult = baseFlowRate / 3.78541; unitLabel = "US Gallons / min"; break; case "gal_hr": finalResult = (baseFlowRate / 3.78541) * 60; unitLabel = "US Gallons / hour"; break; case "m3_sec": finalResult = (baseFlowRate / 1000) / 60; unitLabel = "m³ / sec"; break; case "m3_min": finalResult = baseFlowRate / 1000; unitLabel = "m³ / min"; break; case "m3_hr": finalResult = (baseFlowRate / 1000) * 60; unitLabel = "m³ / hour"; break; case "ft3_sec": finalResult = (baseFlowRate / 28.3168) / 60; unitLabel = "ft³ / sec"; break; case "ft3_min": finalResult = baseFlowRate / 28.3168; unitLabel = "ft³ / min"; break; } // 6. Display Result var displayBox = document.getElementById("resultDisplay"); var resultVal = document.getElementById("flowRateResult"); var resultUnit = document.getElementById("flowRateUnitDisplay"); // Formatting logic: if number is very small or very large, handle decimals nicely var formattedNumber; if (finalResult === 0) { formattedNumber = "0"; } else if (finalResult 1000000) { formattedNumber = finalResult.toExponential(4); } else { formattedNumber = parseFloat(finalResult.toFixed(4)).toString(); // Remove trailing zeros } resultVal.innerHTML = formattedNumber; resultUnit.innerHTML = unitLabel; displayBox.style.display = "block"; }

Leave a Comment