Convert Meters to the fourth to Feet to the fourth

The Meter to the fourth (symbol: m⁴) is a unit of area moment of inertia. The SI unit of second moment of area I (also called area moment of inertia) per ISO 80000-4 §4-13 — captures how a cross-section's area is distributed about a bending axis (centroidal or otherwise), the fundamental cross-section property in beam-bending and column-buckling analysis. The bending-stress formula σ = M·c/I, beam-deflection formula δ = M·L²/(8·E·I) for cantilever uniform-load, and Euler critical-load formula P_cr = π²·E·I/(K·L)² all use I in m⁴. m⁴ is the working unit in structural-analysis research, peer-reviewed engineering literature, finite-element solver inputs (Ansys Mechanical, ABAQUS, NASTRAN, SAP2000, ETABS), and the steel + concrete cross-sectional property output of all major CAD packages (Autodesk Robot, Tekla Structures, RAM Structural System). Reference values: a 0.5 m × 0.5 m square cross-section has I = b·h³/12 = 5.2 × 10⁻³ m⁴; a 200 mm × 200 mm steel HSS hollow tube with 10 mm wall ~5 × 10⁻⁵ m⁴; a typical pole-vault carbon-composite shaft I ~10⁻⁹ m⁴. Convert m⁴ to cm⁴ by multiplying by 10⁸; to in⁴ by multiplying by 2.403 × 10⁶.

It belongs to the metric measurement system.

Meters to the fourth are commonly used in structural beam design, column analysis, and mechanical engineering.

The Foot to the fourth (symbol: ft⁴) is a unit of area moment of inertia. An imperial second-moment-of-area unit equal to ≈ 8.631 × 10⁻³ m⁴ per NIST SP 811 (= exactly 12⁴ = 20,736 in⁴, since 1 ft = 12 in and fourth-power scaling). ft⁴ appears for very-large-cross-section US structural-engineering applications where in⁴ would produce inconveniently large 5-6-digit numbers: reinforced-concrete bridge girders and piers (modern composite-girder bridges with section depths of 6-12 ft), large industrial-tower base flanges, US Bureau of Reclamation hydropower-dam concrete-section analysis, US Army Corps of Engineers lock-and-dam structural elements, and pre-stressed-concrete box-girder bridges. Less common than in⁴ in everyday US structural engineering but shows up consistently when the cross-section size warrants it (e.g., AASHTO LRFD Bridge Design Specifications occasionally use ft⁴ for very-large prestressed-concrete box-girder section properties). Convert ft⁴ to m⁴ by multiplying by 8.631 × 10⁻³; to in⁴ by multiplying by 20,736.

It belongs to the imperial measurement system.

Feet to the fourth are commonly used in structural beam design, column analysis, and mechanical engineering.