When to use this calculator
Mass flow is especially useful when energy balances depend on how much material passes through a process.
Explore the fluids & flow calculators for other questions in this topic. For a related calculation, use the Minor Loss Head Calculator: Estimate fitting or local head loss from a supplied loss coefficient.
PUTTING IT INTO PRACTICE
Mass 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 |
|---|---|
| Density (kg/m³) | 1,000 |
| Volumetric flow (m³/s) | 0.02 |
| Result | 20 kg/s |
- Check the input labels and enter the example values above.
- Apply the relationship: Mass flow = density × volumetric flow.
- The result is 20 kg/s, rounded for display.
How to interpret your result
Density and volume flow must describe the same fluid conditions.
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 mass flow rate calculator useful?
Mass flow is especially useful when energy balances depend on how much material passes through a process.
How do I use the mass flow rate calculator?
Enter density (kg/m³), volumetric flow (m³/s). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Mass flow = density × volumetric flow.
What should I check before using the result?
Density and volume flow must describe the same fluid conditions.
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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