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Mechanical EngineeringP0

Flow Rate Calculator

Calculate volumetric flow rate from pipe diameter and velocity, with unit conversions.

Inputs
Enter your values below
Result
Flow Rate
—
Enter values and click Calculate
Formula
π × (diameter ÷ 2)² × velocity × 3600
Result unit: m³/h

Q = A × v = π(D/2)² × v. Diameter in m, velocity in m/s; ×3600 converts m³/s to m³/h.

Introduction

Calculate the volumetric flow rate through a pipe given its diameter and the fluid velocity. This is the fundamental Q = A × v relationship used in all fluid mechanics.

Calculation Example

100mm pipe at 2 m/s carries 56.5 m³/h.

Inputs: diameter=100, velocity=2
Result: 56.5 m³/h

Engineering Applications

  • •Flow measurement
  • •Pump sizing
  • •Pipeline capacity
  • •Process control

Frequently Asked Questions

How do I convert to GPM?

1 m³/h = 4.403 GPM. Multiply the result by 4.403 for US gallons per minute.

What is typical flow for a 4-inch pipe?

A 4-inch (100mm) pipe at 2 m/s carries about 56 m³/h or 247 GPM.

Related Calculators

Pipe Flow CalculatorPipe Velocity CalculatorFlow Unit Conversion Calculator

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Disclaimer: Calculations are for reference and educational purposes only. Always verify results independently for engineering design. See full disclaimer.