T TibCal

Flow Rate Calculator

Calculate flow rate calculator calculate volumetric discharge flow rate Q from cross-sectional area A and fluid velocity v (Q = A * v). Accurate physics formulas and unit conversions for engineers, students & technicians.

Calculate Volumetric Flow Rate (Q = A · v)

Enter your physical parameters below to compute verified discharge flow metrics.

Pipe cross-sectional area in m^2 (e.g. 0.01 m² = 100 cm²).
Fluid flow velocity in meters per second (e.g. 3.0 m/s).

Calculation Results

Primary Metric Output --
Metric Breakdown 1 --
Metric Breakdown 2 --
Metric Breakdown 3 --
Metric Breakdown 4 --
Metric Breakdown 5 --
Mathematical Standard --

Calculated using verified physical methodology: Volumetric Flow Rate: Q = A \cdot v
Mass Flow Rate: \dot{m} = \rho \cdot Q

*Note: Results represent volume passing through pipe per unit time.

Quick Summary

The Flow Rate Calculator computes volumetric discharge flow rate ($Q = A \cdot v$) from pipe cross-sectional area ($A$) and fluid velocity ($v$) in Liters per minute (L/min), $\text{m}^3/\text{s}$, $\text{m}^3/\text{h}$, and Imperial US GPM.

Formula Explanation

Volumetric Flow Rate: Q = A \cdot v
Mass Flow Rate: \dot{m} = \rho \cdot Q

How It Works

The Flow Rate Calculator multiplies pipe cross-sectional area ($A$ in $\text{m}^2$) by fluid velocity ($v$ in m/s). It outputs flow rate in Liters per minute, $\text{m}^3/\text{s}$, $\text{m}^3/\text{h}$, US Gallons per minute (GPM), and equivalent water mass flow rate ($\dot{m} = \rho Q$).

Step-by-Step Worked Example

Practical Problem: Calculate volumetric flow rate through a water pipe with cross-sectional area $A = 0.01\text{ m}^2$ (100 cm²) flowing at velocity $v = 3.0\text{ m/s}$.

  1. Step 1: Identify Input Parameters: Area $A = 0.01\text{ m}^2$, Velocity $v = 3.0\text{ m/s}$.
  2. Step 2: Apply the Volumetric Flow Rate Formula: $Q = A \cdot v$.
  3. Step 3: Execute Numeric Multiplication for $\text{m}^3/\text{s}$: $Q = 0.01\text{ m}^2 \times 3.0\text{ m/s} = 0.0300\text{ m}^3/\text{s}$.
  4. Step 4: Convert to Liters per Minute (L/min) & GPM: Liters/sec: $0.030 \times 1,000 = 30.0\text{ L/s}$. Liters/min: $30.0 \times 60 = 1,800.00\text{ L/min}$. US GPM: $1,800 \times 0.264172 = 475.51\text{ GPM}$.
  5. Step 5: Calculate Water Mass Flow Rate ($\dot{m}$): $\dot{m} = 1,000\text{ kg/m}^3 \times 0.030\text{ m}^3/\text{s} = 30.00\text{ kg/sec}$ ($108.0\text{ metric tonnes/hour}$).

Real-World Calculation Examples

Scenario 1: Industrial Water Supply Pipe

Parameters: $A = 0.01\text{ m}^2$, $v = 3.0\text{ m/s}$

Result: $Q = 1,800.00\text{ L/min}$ (0.030 m³/s, 475.51 GPM). Main supply line flow.

Scenario 2: Residential Garden Hose Pipe

Parameters: $A = 0.000314\text{ m}^2$ (20mm dia), $v = 1.5\text{ m/s}$

Result: $Q = 28.27\text{ L/min}$ (0.00047 m³/s, 7.47 GPM). Garden hose discharge.

Scenario 3: Fire Hose High-Pressure Nozzle

Parameters: $A = 0.001257\text{ m}^2$ (40mm dia), $v = 20.0\text{ m/s}$

Result: $Q = 1,508.40\text{ L/min}$ (0.0251 m³/s, 398.5 GPM). Firefighting hose jet.

Scenario 4: HVAC Air Duct Ventilation Channel

Parameters: $A = 0.20\text{ m}^2$, $v = 5.0\text{ m/s}$

Result: $Q = 1.000\text{ m}^3/\text{s}$ (3,600 m³/h, 2,118 CFM). Air duct flow rate.

Key Benefits of Using This Calculator

Volumetric & Mass Flow Dual Output

Computes volumetric flow rate ($Q = A \cdot v$) and mass flow rate ($\dot{m} = \rho Q$) simultaneously.

Pipe Sizing & Pump Engineering

Essential for sizing water supply pumps, HVAC ducts, and irrigation systems.

Multi-Unit Readouts

Outputs flow rate in L/min, $\text{m}^3/\text{s}$, $\text{m}^3/\text{h}$, and US GPM.

100% Free & Client-Side

Executes locally in your browser with zero latency or web server transmission.

Frequently Asked Questions (FAQ)

What is volumetric flow rate?

Volumetric flow rate (Q) is the volume of fluid which passes per unit time through a given cross-sectional area (Q = A * v = V / t).

What is the formula for flow rate?

Q = A * v, where A is pipe cross-sectional area in m² and v is average flow velocity in m/s.

What is the SI unit of flow rate?

Cubic meters per second (m³/s); L/min, m³/h, and GPM are also widely used in industry.

How converts m³/s to Liters per minute (L/min)?

Multiply m³/s by 60,000 to get L/min (e.g. 0.03 m³/s = 1,800 L/min).

How converts L/min to US GPM?

Multiply L/min by 0.264172 to obtain US Gallons per Minute (GPM) (e.g. 1,800 L/min = 475.51 GPM).

What is mass flow rate vs volumetric flow rate?

Volumetric flow rate Q = A * v (m³/s); mass flow rate m_dot = rho * Q = rho * A * v (kg/s).

How does pipe diameter affect flow area?

Area A = pi * (d/2)²; doubling pipe diameter quadruples cross-sectional area and quadruples flow rate for the same velocity.

What is average velocity profile in laminar vs turbulent pipe flow?

In laminar flow, maximum centerline velocity v_max = 2 * v_avg; in turbulent flow, v_max = ~1.22 * v_avg.

How relates flow rate to pressure drop in pipes?

According to the Hagen-Poiseuille equation for laminar flow, flow rate Q is directly proportional to pressure drop delta P (Q proportional to delta P * r^4 / L).

What is standard cubic feet per minute (CFM) in HVAC?

CFM measures volumetric airflow rate in cubic feet per minute (1 m³/s = 2,118.88 CFM).

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