The highest wind-force number on the original Beaufort scale is Force 12.
The Beaufort scale was created by Irish hydrographer Francis Beaufort in 1805 and adopted by the Royal Navy during the 19th century. It originally linked wind force to the observable effects of wind on sailing ships, from calm conditions at Force 0 to conditions in which a sailing ship could carry no more sail at Force 12.
The scale was later standardized with descriptions of conditions on land and numerical wind-speed ranges. Modern Beaufort Force 12 corresponds to hurricane-force winds of at least 64 knots, or 118 kilometers per hour, although stronger winds can occur within that category.
A frequent misunderstanding is that Beaufort numbers are direct measurements from an instrument. They are a classification based on wind speed and observed effects. The scale has been extended in some unofficial contexts, but the standard scale ends at Force 12.