Buoyancy Calculator

Calculate the buoyant force, net force, and whether an object floats or sinks using Archimedes' principle: F_b = ρ_fluid × V × g.

Inputs

Object Volume

cu yd

Object Density

kg/m³

Fluid Density

kg/m³

Tab to move between fields

Results

Buoyant Force

98.1 N

Float / Sink

Floats

Object Weight78.48 N

Net Force (+ = up)19.62 N

Fraction Submerged80%

Apparent Weight0 N

How to Use This Calculator

Enter Object Volume, Object Density, and Fluid Density.
Review Buoyant Force (N) and Float / Sink.
Use Object Weight (N) and Net Force (+ = up) to inform your decision.
Use the chart to visualize the results and explore different scenarios by adjusting inputs.

How the result changes with Object Volume

Object Volume	Buoyant Force	Float / Sink
100,000	981,000,000 N	Floats
350,000	3,433,500,000 N	Floats
650,000	6,376,500,000 N	Floats
900,000	8,829,000,000 N	Floats

What each input means

Object Volume: Volume of the submerged object in cubic meters. 0.01 m³ = 10 liters.
Object Density: Average density of the object. Wood ≈ 500–800, steel ≈ 7800, ice ≈ 917 kg/m³.
Fluid Density: Density of the surrounding fluid. Fresh water ≈ 1000, seawater ≈ 1025, mercury ≈ 13,546 kg/m³.

How this is calculated

Worked example, using the default values

Identify Input Parameters
Object Volume = 0.01, Object Density = 800, Fluid Density = 1000 = 3 input(s) provided
Calculate Buoyant Force
98.1 = 98.1
Calculate Float / Sink
Float / Sink
Floats = Floats
Calculate Object Weight
Object Weight
78.48 = 78.48
Calculate Net Force
Net Force
19.62 = 19.62

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