Convection coefficient based on inside area is usually measured using the Watt per Square Meter per Kelvin[W/m²*K] for Heat Transfer Coefficient. Watt per Square Meter per Celcius[W/m²*K], Joule per Second per Square Meter per Kelvin[W/m²*K], Kilocalorie (IT) per Hour per Square Foot per Celcius[W/m²*K] are the few other units in which Convection coefficient based on inside area can be measured.