Compute the buoyant force acting on an immersed or floating body from the density of the displaced fluid and the displaced volume using F = ρ·g·V, for ships, buoys and submerged structures.
排开流体重量等于浮力。
| Item | Formula | Source / Standard |
|---|---|---|
| Buoyant force | F = rho·g·V | Archimedes principle |
| Displaced volume | V = m/rho or submerged volume | displacement |
| Float or sink | Object density vs fluid density | buoyancy criterion |
Constants used on this page and their authoritative sources, for verification and citation
| Constant | Value | Unit | Source |
|---|---|---|---|
| Standard acceleration of gravity g_n | 9.80665 | m·s⁻² | ISO 80000-3 / BIPM conventional value (exact) |
| Density of pure water (4 ℃) | 999.972 | kg·m⁻³ | IAPWS-95 formulation |
| Density of pure water (20 ℃) | 998.207 | kg·m⁻³ | IAPWS-95 formulation |
| Density of standard seawater | 1025 | kg·m⁻³ | UNESCO EOS-80 typical value (page default) |
| Density of dry air (20 ℃, 1 atm) | 1.204 | kg·m⁻³ | ISO 2533 / CIPM air-density formula |
Note: liquid density varies with temperature, salinity and pressure; use the IAPWS-95 (water) or TEOS-10 (seawater) equation of state for precision work.