How to Measure Tornadoes: The EF Scale

The EF Scale


Tornado outside of Erie Kansas

Amy Price


Rate this Article: 

Average: 3.8 (81 votes)

The EF Scale (below) is the standard way to measure tornadoes based on wind damage.

The original Fujita Scale (or F Scale) was developed by Dr. Theodore Fujita. All tornadoes, and other severe local windstorms, were assigned a number according to the most intense damage caused by the storm.

The enhanced F Scale (EF Scale) was implemented in the United States on February 1, 2007. The EF scale uses three-second wind gust estimates based on a more detailed system for assessing damage, taking into account different building materials.

Note: Click on the chart below to enlarge.


The 2009 Old Farmer's Almanac

What do you want to read next?

Reader Comments

Leave a Comment


this was not helpful

this is helpful

This is helpful to me because you are probably not understanding it as much as I am so ask for help.

Free Beginners Garden Guide

Vegetable Gardening for Beginners!
Your complete guide on how to grow a vegetable garden—from scratch!


You will also be subscribed to our Almanac Companion Newsletter