Convert Square inches per hour to Square millimetres per hour

Convert Square inches per hour (in²/h) to Square millimetres per hour (mm²/h) instantly and accurately.

Square inches per hour (in²/h)
Square millimetres per hour (mm²/h)

Conversion Formula

mm²/h = in²/h × 645.16

About Square inches per hour

The square inch per hour (in²/h) equals 0.0254²/3600 ≈ 1.792 × 10⁻⁷ m²/s. It is found in US heat-transfer and diffusion textbooks that use the BTU-inch-hour unit system alongside thermal diffusivity tables. 1 in²/h ≈ 0.1792 cSt.

About Square millimetres per hour

The square millimetre per hour (mm²/h) equals 1/(3.6 × 10⁹) m²/s ≈ 2.78 × 10⁻¹⁰ m²/s. It appears in materials science for solid-state diffusion and thin-film growth studies where hourly timescales are more natural than seconds. 1 mm²/h = 1/3600 mm²/s = 1/3600 cSt.

Quick Reference Table

Square inches per hour (in²/h)Square millimetres per hour (mm²/h)
1 in²/h645.16 mm²/h
2 in²/h1290.32 mm²/h
5 in²/h3225.8 mm²/h
10 in²/h6451.6 mm²/h
25 in²/h16129 mm²/h
50 in²/h32258 mm²/h
100 in²/h64516 mm²/h

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