Convert Pound square feet to Kilogram square metres
Convert Pound square feet (lb·ft²) to Kilogram square metres (kg·m²) instantly and accurately.
Conversion Formula
kg·m² = lb·ft² × 0.04214011009
About Pound square feet
The pound square foot (lb·ft²) equals ≈0.04214 kg·m², the dominant imperial unit for machine and vehicle rotational inertias. Aircraft control-surface counterbalancing, propeller blade inertia, and turbocharger rotor dynamics are specified in lb·ft²; steam turbine discs and helicopter tail-rotor assemblies: 1-10 000 lb·ft². 1 lb·ft² ≈0.04214 kg·m² = 144 lb·in² ≈0.03108 slug·ft².
About Kilogram square metres
The kilogram square metre (kg·m²) is the SI coherent derived unit of moment of inertia. It defines the rotational analogue of mass in Newton's second law: τ = Iα (torque in N·m, angular acceleration in rad/s²). A solid disc of 10 kg and 0.5 m radius has I = 1.25 kg·m². Electric motor rotors: 0.001-10 kg·m². Wind turbine rotors: 10⁶-10⁸ kg·m². 1 kg·m² = 10 000 kg·cm² ≈0.7376 slug·ft².
Quick Reference Table
| Pound square feet (lb·ft²) | Kilogram square metres (kg·m²) |
|---|---|
| 1 lb·ft² | 0.0421401 kg·m² |
| 2 lb·ft² | 0.0842802 kg·m² |
| 5 lb·ft² | 0.210701 kg·m² |
| 10 lb·ft² | 0.421401 kg·m² |
| 25 lb·ft² | 1.0535 kg·m² |
| 50 lb·ft² | 2.10701 kg·m² |
| 100 lb·ft² | 4.21401 kg·m² |