Conversion of Wind Speed To Pressure

The basic formula for converting a wind speed to wind load is: 0.6 x velocity² = wind load.  However, to get a true design wind speed is a lot more complex; various factors have to be applied including roof self-weight, internal pressure and local pressure coefficients. 

The most influential of these factors is generally the local pressure factor, but internal pressure can also have a profound influence—particularly on unlined structures.