Buoyancy and floating equilibrium
Assumes a uniform fluid, a rigid body and your own g. The actual immersion can differ from the equilibrium one.
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- Check before download
Assumes a uniform fluid, a rigid body and your own g. The actual immersion can differ from the equilibrium one. The prism draft needs a constant cross-section, and a body that sinks has no equilibrium fraction. The equilibrium compares the decimal quantities you entered using exact unit scales; the displayed numbers are rounded.
Model, grammar and limits
Fb=ρfluid·Vsub·g; W=m·g; V_eq=m/ρfluid
Numbers can have up to 48 characters, with a decimal point or e, and no thousands separators. Curves use 2 to 501 samples plus up to 16 section endpoints. Use up to 32 forces or sources and up to 16 sections. Springs take 1 to 20 periods with at least 8 samples per period; pendulum angles run from 0 to 179°. Magnus covers −40 to 35 °C over water and −40 to 0 °C over ice; relative humidity 0 to 100%, pressure 5 to 200 kPa, and vapor pressure must be below total pressure. Backup is limited to 1 MiB. Invalid, non-unique or unresolved data are rejected.
Results are numerical idealizations in SI units, shown with up to 10 digits; CSV keeps the numeric values and units. 9.80665 m/s² is the conventional standard g, not local gravity. Uncertainty in your inputs or the model is not estimated, and nothing here is a physical approval.
Calculation and backup stay in this browser. Workers stop after 15 seconds, or when you edit, reset or cancel. Inputs are never uploaded or stored. Input data, formulas and filenames are never sent. Only with your optional consent, Refentra sends aggregate counts of actions and outcomes, without input content.
Use the chosen model
- Model, grammar and limits
Choose mass or body density, then enter the total volume, the fluid density, the submerged percentage and gravity. Select prism only when you know a meaningful height.
- Calculate
Use a volume of 2 L, mass of 1 kg, fluid of 1000 kg/m³, immersion of 50% and g = 10 m/s². Buoyancy and weight are both 10 N, and the equilibrium volume is 1 L.
- Download CSV report
Compare the net upward force at the immersion you chose with the floating equilibrium. For a prism with a constant section 1 m high, the equilibrium draft is 0.5 m.
Model questions
What does this result mean?
The submerged percentage you choose describes the current state, while the equilibrium immersion is calculated from the mass and the fluid density. The two need not agree.
How do I resolve rejected or missing input?
Check L against m³ and the mass mode against the density mode. Immersion must be 0…100%. Geometry or density that is not positive can't describe this model, so it is rejected.
What are the limits of this tool?
An ideal static Archimedes model in a uniform fluid. It is not about stability, waves or certifying a vessel. Draft by height applies only to the prism geometry the tool describes.