Convert Square millimetres per minute to Square feet per hour

Convert Square millimetres per minute (mm²/min) to Square feet per hour (ft²/h) instantly and accurately.

Square millimetres per minute (mm²/min)
Square feet per hour (ft²/h)

Conversion Formula

ft²/h = mm²/min × 0.000645834625

About Square millimetres per minute

The square millimetre per minute (mm²/min) equals 1/60 000 000 m²/s. It appears in material testing standards where thermal diffusivity of polymers and composites is measured over minute-scale heating pulses. ASTM and ISO laser-flash methods sometimes report in mm²/min as an intermediate step. 1 mm²/min = 1e-6/60 m²/s ≈ 1.667 × 10⁻¸ m²/s.

About Square feet per hour

The square foot per hour (ft²/h) equals ≈2.581 × 10⁻⁵ m²/s and is the dominant unit in US engineering practice for thermal diffusivity of building materials and industrial insulation. ASHRAE handbooks, Perry's Chemical Engineers' Handbook, and NFPA fire-resistance tables all list diffusivity in ft²/h. Steel: ≈0.4-0.5 ft²/h; concrete: ≈0.023 ft²/h; mineral wool: ≈0.005 ft²/h. 1 ft²/h = 0.09290304/3600 m²/s.

Quick Reference Table

Square millimetres per minute (mm²/min)Square feet per hour (ft²/h)
1 mm²/min0.000645835 ft²/h
2 mm²/min0.00129167 ft²/h
5 mm²/min0.00322917 ft²/h
10 mm²/min0.00645835 ft²/h
25 mm²/min0.0161459 ft²/h
50 mm²/min0.0322917 ft²/h
100 mm²/min0.0645835 ft²/h

→ Full Thermal Diffusivity Converter