When to use this calculator
Archimedes’ principle equates buoyant force to the weight of displaced fluid.
Explore the fluids & flow calculators for other questions in this topic. For a related calculation, use the Capillary Rise Calculator: Estimate capillary rise or depression in a small circular tube.
PUTTING IT INTO PRACTICE
Buoyant Force: 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 |
|---|---|
| Fluid density (kg/m³) | 1,000 |
| Displaced volume (m³) | 0.01 |
| Gravity (m/s²) | 10 |
| Result | 100 N |
- Check the input labels and enter the example values above.
- Apply the relationship: Buoyant force = fluid density × displaced volume × gravity.
- The result is 100 N, rounded for display.
How to interpret your result
Use submerged displaced volume, not total object volume when only partly immersed.
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 buoyant force calculator useful?
Archimedes’ principle equates buoyant force to the weight of displaced fluid.
How do I use the buoyant force calculator?
Enter fluid density (kg/m³), displaced volume (m³), gravity (m/s²). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Buoyant force = fluid density × displaced volume × gravity.
What should I check before using the result?
Use submerged displaced volume, not total object volume when only partly immersed.
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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