<Li> The rating of any given tornado is of the most severe damage to any well - built frame home or comparable level of damage from engineering analysis of other damage . </Li> <Li> Since the Fujita scale is based on the severity of damage resulting from high winds, an F6 or an F7 tornado is a theoretical construct . Structural damage cannot exceed total destruction, which constitutes an F5 . A tornado with wind speeds greater than 319 miles per hour (513 km / h) is theoretically possible, and the 1999 Bridge Creek - Moore Tornado may have been such an event . However, no such wind speed has ever been recorded and that measurement was not near ground level . </Li> <Table> <Tr> <Td> Scale </Td> <Td_colspan="2"> Wind speed estimate </Td> <Td> Path width </Td> <Td_colspan="2"> Potential damage </Td> </Tr> <Tr> <Td> mph </Td> <Td> km / h </Td> </Tr> <Tr> <Td> F0 </Td> <Td> 40--72 </Td> <Td> 64--116 </Td> <Td> 6--17 yards (5.5--15.5 m) </Td> <Td> Light damage . <P> Some damage to chimneys; branches broken off trees; shallow - rooted trees pushed over; sign boards damaged . </P> </Td> <Td> </Td> </Tr> <Tr> <Td> F1 </Td> <Td> 73--112 </Td> <Td> 117--180 </Td> <Td> 18--55 yards (16--50 m) </Td> <Td> Moderate damage . <P> The lower limit is the beginning of hurricane wind speed; peels surface off roofs; mobile homes pushed off foundations or overturned; moving vehicles pushed off the roads; attached garages may be destroyed . </P> </Td> <Td> </Td> </Tr> <Tr> <Td> F2 </Td> <Td> 113--157 </Td> <Td> 181--253 </Td> <Td> 56--175 yards (51--160 m) </Td> <Td> Significant damage . <P> Roofs torn off frame houses; mobile homes demolished; boxcars overturned; large trees snapped or uprooted; highrise windows broken and blown in; light - object missiles generated . </P> </Td> <Td> </Td> </Tr> <Tr> <Td> F3 </Td> <Td> 158--206 </Td> <Td> 254--332 </Td> <Td> 176--566 yards (161--518 m) </Td> <Td> Severe damage . <P> Roofs and some walls torn off well - constructed houses; trains overturned; most trees in forest uprooted; heavy cars lifted off the ground and thrown . </P> </Td> <Td> </Td> </Tr> <Tr> <Td> F4 </Td> <Td> 207--260 </Td> <Td> 333--418 </Td> <Td> 0.3--0.9 miles (0.48--1.45 km) </Td> <Td> Devastating damage . <P> Well - constructed houses leveled; structures with weak foundations blown away some distance; cars thrown and large missiles generated . </P> </Td> <Td> </Td> </Tr> <Tr> <Td> F5 </Td> <Td> 261--318 </Td> <Td> 419--512 </Td> <Td> 1.0--3.1 miles (1.6--5.0 km) </Td> <Td> Incredible damage . <P> Strong frame houses lifted off foundations and carried considerable distances to disintegrate; automobile sized missiles fly through the air farther than 100 meters (110 yards); trees debarked; steel reinforced concrete structures badly damaged and skyscrapers toppled </P> </Td> <Td> </Td> </Tr> </Table> <Tr> <Td> Scale </Td> <Td_colspan="2"> Wind speed estimate </Td> <Td> Path width </Td> <Td_colspan="2"> Potential damage </Td> </Tr>

What is the wind speed of f1 tornado