Flow Rate Calculator
Calculate flow rate from volume and time
Table of Contents
How to Use
- Enter the volume of fluid that flowed
- Enter the time it took for that volume to flow
- Select your preferred units
- Click calculate to see the flow rate
- View results in multiple unit formats
What is Flow Rate?
Flow rate is the amount of fluid (liquid or gas) that flows past a point in a given amount of time. It's a fundamental concept in physics, engineering, and fluid mechanics used to measure how quickly substances move through pipes, channels, or open areas.
Common units for flow rate include liters per minute (L/min), gallons per minute (GPM), milliliters per second (ml/s), and cubic meters per hour (m³/h).
Flow Rate Formula
Flow rate is calculated using the simple formula:
Flow Rate = Volume / Time
Where:
- Volume = amount of fluid that flows
- Time = duration over which the volume flows
- Flow Rate = volume per unit time
Types of Flow Rate
There are two main concepts related to flow rate:
- Volumetric Flow Rate: Volume of fluid per unit time (e.g., L/min)
- Mass Flow Rate: Mass of fluid per unit time (e.g., kg/s)
This calculator focuses on volumetric flow rate, which is most commonly used in practical applications.
Applications of Flow Rate
- Water systems: Municipal water supply and sewage treatment
- HVAC systems: Air conditioning and ventilation flow calculations
- Medical: IV drip rates and respiratory equipment
- Manufacturing: Process fluid delivery systems
- Hydraulics: Oil flow in hydraulic systems
- Laboratory: Gas and liquid flow in experiments
- Environmental: River and stream flow monitoring
Frequently Asked Questions
- What's the difference between flow rate and velocity?
- Flow rate measures the volume of fluid passing a point per unit time (e.g., L/min). Velocity measures how fast the fluid is moving (e.g., m/s). For a given pipe, flow rate depends on both the velocity and the cross-sectional area.
- How do I convert between different flow rate units?
- Common conversions: 1 L/min = 0.264 GPM, 1 L/min = 16.67 ml/s, 1 m³/h = 16.67 L/min. This calculator automatically converts between units.
- Why is flow rate important in plumbing?
- Flow rate determines water pressure and usage in homes and buildings. Building codes specify minimum flow rates for fixtures. Knowing flow rate helps with sizing pipes and ensuring adequate water pressure.
- How does pipe diameter affect flow rate?
- For the same pressure, larger diameter pipes allow higher flow rates. Flow rate is proportional to the cross-sectional area. A pipe with twice the diameter can have 4 times the flow rate (with same velocity).
- Can flow rate be negative?
- Technically, flow rate is always positive in magnitude, but direction can be specified. In some applications, negative flow indicates reverse flow direction. This calculator uses positive values.