How is ship displacement calculated?

Displacement (Δ) = ρ × ∇ where ρ = water density (1025 kg/m³ seawater) and ∇ = submerged volume (m³). For box-shaped hull: ∇ = L × B × T × Cb where Cb = block coefficient.

What is the block coefficient?

Cb = Δ / (L × B × T × ρ). Typical values: tankers 0.80–0.85 (full form), container ships 0.60–0.65, frigates 0.45–0.55 (fine form).

Ship Displacement & Buoyancy Calculator — Archimedes Principle

Calculate ship displacement, deadweight tonnage (DWT), draft, and block coefficient. Apply Archimedes' principle to vessel buoyancy.

Tap constants to insert

Physical Constants Reference

Constant	Symbol	Value	Units
Speed of light	c	2.99792458×10⁸	m/s
Planck's constant	h	6.62607015×10⁻³‴	J·s
Boltzmann constant	kʙ	1.380649×10⁻²³	J/K
Avogadro's number	Nₐ	6.02214076×10²³	mol⁻¹
Gravitational constant	G	6.6743×10⁻¹¹	N·m²/kg²
Gas constant	R	8.31446	J/(mol·K)
Elementary charge	e	1.602176634×10⁻¹⁹	C
Electron mass	mₑ	9.1093837015×10⁻³¹	kg
Proton mass	mₚ	1.67262192369×10⁻²⁷	kg
Fine-structure constant	α	7.2973525693×10⁻³	dimensionless

How to use this calculator

1
Enter engineering parameters
Enter the structural dimensions, material properties, loads, pressures, or system specifications into the Ship Displacement & Buoyancy Calculator — Archimedes Principle.
2
Select units and standards
Select the appropriate unit system (SI or Imperial) and applicable design standard (ISO, ASTM, NIST, ACI, etc.).
3
Run the calculation
Press Calculate to apply the engineering formula and compute the result.
4
Review against tolerances
Review the computed values against standard engineering tolerances, safety factors, or code-specified limits.

Formula

Result = f(load, geometry, material, safety factor)

load: Applied force, pressure, moment, or demand entered into the Ship Displacement.
geometry: Dimensions, cross-section, span, or shape of the element under analysis.
material: Material properties such as yield strength, modulus, density, or conductivity.
safety factor: Design factor applied to the nominal result per the governing code or standard.
Result: Computed stress, deflection, capacity, efficiency, or design value.

Engineering results must be checked against the applicable code (ISO, ASTM, ACI, NIST, etc.) and tolerances.

Glossary and Definitions

Load: An external force, pressure, moment, or demand applied to a structure or component.
Safety factor: A design multiplier that reduces allowable stress below the nominal capacity to account for uncertainty.
Yield strength: The stress at which a material begins to deform plastically and will not return to its original shape.
Deflection: The degree to which a structural element bends under load, measured as displacement from rest.
Ship displacement calculator: A key concept referenced by the Ship Displacement: Calculate ship displacement, deadweight tonnage (DWT), draft, and block coefficient. Apply Archimedes' principle to vessel buoyancy.
Deadweight tonnage: A key concept referenced by the Ship Displacement: Calculate ship displacement, deadweight tonnage (DWT), draft, and block coefficient. Apply Archimedes' principle to vessel buoyancy.
Ship draft calculator: A key concept referenced by the Ship Displacement: Calculate ship displacement, deadweight tonnage (DWT), draft, and block coefficient. Apply Archimedes' principle to vessel buoyancy.
Block coefficient: A key concept referenced by the Ship Displacement: Calculate ship displacement, deadweight tonnage (DWT), draft, and block coefficient. Apply Archimedes' principle to vessel buoyancy.

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