When to use this calculator
This relationship connects the amount of fluid passing a section each second with its average speed.
Explore the fluids & flow calculators for other questions in this topic. For a related calculation, use the Angular Momentum Calculator: Calculate scalar angular momentum for a rigid rotor.
PUTTING IT INTO PRACTICE
Volumetric Flow Rate: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Cross-sectional area (m²) | 0.01 |
| Average flow velocity (m/s) | 2 |
| Result | 0.02 m³/s |
- Check the input labels and enter the example values above.
- Apply the relationship: Flow = cross-sectional area × average velocity.
- The result is 0.02 m³/s, rounded for display.
How to interpret your result
Use the average velocity across the flowing cross section.
Use the fluid properties at the relevant conditions. Gauge pressure is measured relative to a reference and differs from absolute pressure. Average flow velocity and characteristic length must match the geometry being modelled.
Frequently asked questions
Should hydrostatic pressure be added to atmospheric pressure?
Add the surface absolute pressure when an absolute result is needed. The basic liquid-column calculation alone gives the pressure increase with depth.
When is the volumetric flow rate calculator useful?
This relationship connects the amount of fluid passing a section each second with its average speed.
How do I use the volumetric flow rate calculator?
Enter cross-sectional area (m²), average flow velocity (m/s). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Flow = cross-sectional area × average velocity.
What should I check before using the result?
Use the average velocity across the flowing cross section.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see OpenStax: fluids, density and pressure ↗. This is a topic reference, not an external review or endorsement of this tool.
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