What does the Enhanced Fujita scale measure?

The EF scale rates tornado intensity from EF0 to EF5 based on the damage caused to 28 damage indicators such as homes, schools and trees. Each rating maps to an estimated 3-second gust wind speed; ratings are assigned after the storm during a damage survey, not measured in real time.

How fast are EF5 tornado winds?

An EF5 tornado has estimated 3-second gust winds over 200 mph (over 322 km/h). At that intensity, strong frame houses are leveled and swept off their foundations, vehicles are thrown more than 100 metres, and steel-reinforced structures suffer critical damage.

What is the difference between the F scale and the EF scale?

The original Fujita (F) scale, used from 1971, linked damage to a single estimated wind speed that later proved too high. The Enhanced Fujita scale replaced it in the US in 2007, using 28 detailed damage indicators and more realistic wind estimates while keeping the familiar 0-to-5 numbering.

Why are EF ratings based on damage and not measured winds?

Tornadoes rarely pass over anemometers, and most weather instruments cannot survive the strongest winds. Surveyors therefore infer the wind that caused the observed damage. This means a violent tornado over open country can be under-rated simply because it hit few structures.

What is the minimum wind for an EF0 tornado?

EF0, the weakest category, begins at an estimated 65 mph (105 km/h) gust and causes light damage such as peeled roof surfaces and broken tree branches. Below 65 mph the event is not rated as a tornado on the EF scale.

What is the Enhanced Fujita Scale Reference?

Complete Enhanced Fujita (EF) tornado scale reference from EF0 to EF5 with 3-second gust wind speeds in mph and km/h, damage descriptions, and a wind-speed-to-rating classifier. It runs free in your browser on Gera Tools, with nothing uploaded.

Enhanced Fujita Scale Reference

Name: Enhanced Fujita Scale Reference
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

Rating tornado intensity from EF0 to EF5

This reference covers the full Enhanced Fujita scale, the system used in the United States since 2007 to classify tornado intensity. Each category from EF0 to EF5 lists its estimated 3-second gust wind speed in both mph and km/h alongside the characteristic damage. A classifier maps any entered gust speed to its rating.

How it works

The EF scale is damage-based. After a tornado, surveyors inspect 28 damage indicators (building types, trees and structures) and judge the degree of damage to each. From that they estimate the wind gust that would produce it, then read off the EF category whose range contains that gust:

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

The classifier on this page converts km/h to mph when needed (mph = km/h / 1.609344) and returns the matching band. Speeds below 65 mph are not rated as tornadoes.

What each category looks like on the ground

Understanding damage descriptions helps when reading post-event surveys or making sense of historical records:

EF0 (65–85 mph): Light damage. Peeled roof surface material, broken branches, shallow-rooted trees pushed over, some sign boards damaged. Looks like strong thunderstorm wind damage to the untrained eye.

EF1 (86–110 mph): Moderate damage. Roofs stripped of shingles, mobile homes overturned or badly damaged, moving vehicles pushed off roads, windows blown out of well-constructed buildings.

EF2 (111–135 mph): Considerable damage. Roofs torn off frame homes, mobile homes completely destroyed, large trees snapped or uprooted, boxcars overturned, light-object missiles generated.

EF3 (136–165 mph): Severe damage. Entire stories of well-constructed homes destroyed, severe damage to large buildings such as shopping centres, trains overturned, trees debarked, heavy cars lifted and thrown.

EF4 (166–200 mph): Devastating damage. Well-constructed homes completely levelled, cars thrown and disintegrated, small missiles generated.

EF5 (over 200 mph): Incredible damage. Strong frame houses swept off foundations and destroyed, steel-reinforced concrete structures critically damaged, automobile-sized missiles.

Why ratings are assigned after the storm, not during

Most people expect tornado intensity to come from direct wind measurements, but tornadoes rarely pass over functioning weather instruments capable of surviving the strongest winds. Portable Doppler radar such as NOAA’s DOW units can measure Doppler velocities near the tornado, but those are radial velocities at altitude — not the 3-second surface gust the EF scale uses.

The damage-based approach has an important consequence: a violent EF5 tracking over open farmland may only be rated EF2 because there were few structures to damage. This means historical tornado records almost certainly under-rate many rural events, and any statistical analysis of EF-scale frequency needs to account for population density and structure availability along the path.

Tips and notes

Ratings reflect the worst damage anywhere along the path, so a brief touchdown over a strong building can earn a high rating.
Mobile homes are the most vulnerable structure type on the scale — EF1 winds (86–110 mph) can already overturn them.
The original Fujita (F) scale used wind-speed estimates later found to be too high; the EF revision lowered the implied speeds in each category while keeping the same 0–5 numbering.
Canada adopted a modified version called the Enhanced Fujita Scale for Canada (EF-CAN) in 2013, with damage indicators calibrated to Canadian construction standards.