Convert Pound square feet to Slug square inches

Convert Pound square feet (lb·ft²) to Slug square inches (slug·in²) instantly and accurately.

Pound square feet (lb·ft²)
Slug square inches (slug·in²)

Conversion Formula

slug·in² = lb·ft² × 4.475656825

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 Slug square inches

The slug square inch (slug·in²) equals ≈9.415 × 10⁻³ kg·m², used in US aerospace guidance and flight mechanics. Pre-metric inertial navigation unit (INU) test reports and NACA stability-derivative tables listed gyroscope platform inertia in slug·in²; US autopilot servo actuator sizing also uses slug·in². 1 slug·in² ≈9.415 × 10⁻³ kg·m² ≈32.17 lb·in².

Quick Reference Table

Pound square feet (lb·ft²)Slug square inches (slug·in²)
1 lb·ft²4.47566 slug·in²
2 lb·ft²8.95131 slug·in²
5 lb·ft²22.3783 slug·in²
10 lb·ft²44.7566 slug·in²
25 lb·ft²111.891 slug·in²
50 lb·ft²223.783 slug·in²
100 lb·ft²447.566 slug·in²

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