A tornado that’s 500 meters in diameter looks a lot more ominous than the average twister, which is “only” 150 meters across. All other things being equal, larger tornadoes are more damaging, but size is not related to wind speed. Instead, wind speed increases along with the difference between atmospheric pressure inside the funnel, and the pressure outside it (the core pressure difference). The larger the core pressure difference, the faster the winds. But at a given wind speed, a larger tornado will do more total damage because it will hit more objects. The Fujita scale estimates tornado damage.