Tornado EF Scale Calculator

Tornado EF Scale Calculator

Look up the corresponding Enhanced Fujita rating for a given estimated tornado wind speed.

Reference: Enhanced Fujita (EF) Scale

EF0: 65-85 mph | EF1: 86-110 | EF2: 111-135 | EF3: 136-165 | EF4: 166-200 | EF5: 200+

Example

An estimated 150 mph wind speed:

EF3

Why EF Ratings Are Assigned After the Fact

The Enhanced Fujita Scale rates tornado intensity based on estimated wind speed derived from surveying actual structural and vegetation damage after the storm passes, since tornadoes are rarely directly measured by wind instruments during the event itself.

Why Ratings Take Days, Not Minutes

This is exactly why EF ratings are typically assigned in the days following a tornado - National Weather Service survey teams inspect the damage path in person, comparing observed damage against detailed damage indicators to arrive at the most accurate rating, rather than issuing a rating in real time during the event.