What Is a Foot? History and Modern Use

Definition of a Foot

A foot (plural: feet, symbol: ft or ′) is a unit of length in the imperial and US customary measurement systems. One foot is defined as exactly 0.3048 meters (30.48 centimeters) or 12 inches. Three feet make one yard, and 5,280 feet make one mile. The foot is one of the oldest units of measurement still in active use today.

Key Facts and Formulas

• 1 foot = 12 inches = 0.3048 meters = 30.48 cm
• 1 meter = 3.28084 feet
• 1 yard = 3 feet
• 1 mile = 5,280 feet
• Feet to meters: meters = feet × 0.3048
• Meters to feet: feet = meters × 3.28084

History of the Foot

Ancient Origins

The foot as a measurement unit dates back thousands of years. Ancient Egyptians used a unit called the “foot” that was about 30 cm, remarkably close to the modern value. The Greeks had a foot (pous) of about 30.8 cm, and the Romans used the pes at about 29.6 cm. These measurements were all based on the approximate length of an adult male's foot — one of the most natural and universally available measuring tools.

Medieval Standardization

During the Middle Ages, the foot varied from region to region across Europe. English kings attempted to standardize it multiple times. In the 12th century, the foot was defined as the length of King Henry I's arm from his nose to his thumb. Later, the foot was set at 12 inches, with the inch defined by King Edward II in 1324 as the length of three barleycorns laid end to end. This 12-inch foot became the English standard.

The 1959 International Agreement

The modern foot was precisely defined by the international yard and pound agreement of 1959, signed by the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa. This agreement defined the international yard as exactly 0.9144 meters, making one foot exactly 0.3048 meters. This definition remains in effect today.

Worked Examples

Example 1: Convert 6 feet to meters

• Step 1: Multiply by 0.3048.
• Step 2: 6 × 0.3048 = 1.8288 meters.
• Result: 6 feet = 1.83 meters (rounded).

Example 2: Convert 10 meters to feet

• Step 1: Multiply by 3.28084.
• Step 2: 10 × 3.28084 = 32.8084 feet.
• Result: 10 meters ≈ 32.81 feet (or 32 feet 9.7 inches).

Example 3: Convert 5 feet 9 inches to centimeters

• Step 1: Convert to total inches: (5 × 12) + 9 = 69 inches.
• Step 2: Convert inches to cm: 69 × 2.54 = 175.26 cm.
• Result: 5′9″ = 175.26 cm.

Use our feet to meters converter for instant, precise results.

Quick Reference Table

Where Feet Are Used Today

United States

The US uses feet as its primary length unit for everyday purposes: human height (5′10″), room dimensions (12 × 15 ft), real estate (square feet), altitude, and construction. Virtually all architectural plans, building codes, and construction materials in the US are measured in feet and inches.

Aviation (Worldwide)

Aircraft altitude is measured in feet globally, even in countries that otherwise use the metric system. A cruising altitude of 35,000 feet (10,668 m) is standard for commercial flights. This convention exists for international standardization and safety.

United Kingdom

The UK officially uses the metric system but still commonly uses feet for personal height and some informal distance estimates. Road signs show miles, and heights of mountains are sometimes given in feet alongside meters.

The Survey Foot

The US previously used a slightly different “survey foot” (1 ft = 1200/3937 meters = 0.30480061 m) for land surveying. This differed from the international foot by about 2 parts per million. As of January 1, 2023, the US officially retired the survey foot in favor of the international foot for all purposes, ending decades of dual definitions.

Frequently Asked Questions

How long is a foot in meters?

One foot is exactly 0.3048 meters (30.48 centimeters), as established by the 1959 international yard and pound agreement.

Why is a foot called a foot?

The foot gets its name from the human foot. Ancient civilizations used the length of a man's foot as a natural measuring standard. Different cultures had slightly different lengths, ranging from about 25 to 35 cm, until it was standardized.

How many inches are in a foot?

There are exactly 12 inches in one foot. This has been the standard since medieval England. Use our inches to centimeters converter for related conversions.

What countries still use feet for measurement?

The United States uses feet in everyday life. The UK uses feet informally for height and some distances. Canada and a few other countries use feet in limited contexts, mainly for aviation altitude and human height. Worldwide, aviation uses feet for altitude.