Fujita Scale (F-Scale) & Enhanced Fujita Scale (EF-Scale) Tornado Damage Calculator

What is the Fujita scale?

The Fujita scale (often called the F-scale) is a tornado intensity scale introduced in 1971 by meteorologist Dr. Tetsuya Theodore Fujita. It classifies tornadoes from F0 (weakest) to F5 (incredible damage) based on estimated wind speeds and the type of damage observed after the storm.

Because direct wind measurements inside tornadoes are extremely rare, meteorologists and engineers infer wind speeds from damage to buildings, trees, and infrastructure. The original F-scale was widely used in the United States until 2007 and is still referenced in historical records and some international datasets.

Enhanced Fujita (EF) scale vs. original Fujita scale

In 2007, the United States adopted the Enhanced Fujita (EF) scale to improve the relationship between damage and estimated wind speed. The EF-scale keeps the same 0–5 rating system but:

• Uses detailed damage indicators (e.g., specific building types, trees, towers).
• Defines multiple degrees of damage for each indicator.
• Assigns revised wind speed ranges that better match engineering knowledge.

As a result, an EF3 tornado causes roughly the same level of damage as an F3 tornado, but the wind speed range is different (generally lower in the EF-scale).

Approximate EF-scale wind speed ranges

Fujita scale categories and typical damage

The table below summarizes the original Fujita scale categories and typical damage patterns. These descriptions are simplified for education; official surveys use more detailed criteria.

F0 – Gale tornado

• Wind: 40–72 mph (64–116 km/h)
• Branches broken off trees, shallow-rooted trees pushed over.
• Minor roof damage, loose shingles or siding peeled off.
• Signs bent, small objects blown around.

F1 – Moderate tornado

• Wind: 73–112 mph (117–180 km/h)
• Mobile homes pushed off foundations or overturned.
• Roofs partially stripped, windows broken.
• Large tree limbs snapped, some trees uprooted.

F2 – Significant tornado

• Wind: 113–157 mph (181–253 km/h)
• Roofs torn off well-built houses.
• Mobile homes demolished.
• Large trees uprooted, light objects turned into dangerous missiles.

F3 – Severe tornado

• Wind: 158–206 mph (254–332 km/h)
• Entire stories of well-constructed houses destroyed.
• Trains overturned, heavy vehicles lifted and thrown.
• Severe damage to large buildings, walls and roofs torn away.

F4 – Devastating tornado

• Wind: 207–260 mph (333–418 km/h)
• Well-constructed houses leveled; structures blown off foundations.
• Cars thrown significant distances, large debris becomes lethal missiles.
• Severe damage to high-rise buildings and strong structures.

F5 – Incredible tornado

• Wind: 261–318 mph (419–512 km/h)
• Strong frame houses swept completely from foundations.
• Debarked trees, heavy objects (cars, machinery) carried long distances.
• Massive structural damage; reinforced concrete structures seriously damaged.

How the calculator estimates a Fujita or EF rating

This tool uses your input wind speed and compares it to the official wind speed ranges for either the original Fujita scale or the Enhanced Fujita scale. The logic is:

The damage-based helper works in the opposite direction: you choose a simplified damage description, and the tool highlights the most likely EF category and its wind range.

Limitations and proper use

• Not an official rating: Only trained meteorologists and engineers can assign official F or EF ratings, usually under the authority of a national weather service.
• Damage depends on construction quality: The same wind speed can cause very different damage to a well-built structure vs. a poorly built one.
• Wind speeds are estimates: Even official EF ratings are based on inferred wind speeds, not direct measurements.
• Safety first: Never delay seeking shelter to observe or photograph a tornado in order to “rate” it.

Practical safety guidance by EF category

Regardless of the rating, all tornadoes are dangerous. However, higher categories imply more severe consequences if you are not in a proper shelter.

• EF0–EF1: Seek shelter in an interior room on the lowest floor, away from windows.
• EF2–EF3: A basement or purpose-built storm shelter is strongly recommended.
• EF4–EF5: Only engineered storm shelters or underground shelters offer reliable protection.

Always follow guidance from your local meteorological service, emergency management agencies, and building codes for tornado-safe construction and sheltering.