UnitConvConvert
ft
Lengthimperialaviationconstruction

What is a foot?

The international aviation altitude standard and US building unit

Definition

The foot equals 30.48 centimeters exactly and is one of the oldest length units in human history. It is the international aviation standard for altitude — commercial airliners cruise at 35,000 feet. In the US, building dimensions, human height and elevation are all expressed in feet. 1 foot = 12 inches.

Common uses

  • Aircraft cruising altitude in international aviation
  • US building heights, ceiling heights and room dimensions
  • Mountain elevations on global maps (Everest = 29,032 ft)

🌍 Real-world scale

Airliners cruise at 35,000 ft (10.7 km). Mount Everest is 29,032 ft (8,849 m). A standard US ceiling is 8 ft (2.44 m).

Convert from feet

14 conversions
Foot to Meter1 ft = 0.3048 mFoot to Kilometer1 ft = 0.0003048 kmFoot to Centimeter1 ft = 30.48 cmFoot to Millimeter1 ft = 304.8 mmFoot to Mile1 ft = 0.0001894 miFoot to Yard1 ft = 0.3333 ydFoot to Inch1 ft = 12 inFoot to Nautical Mile1 ft = 0.0001646 nmiFoot to Micrometer1 ft = 304,800 µmFoot to Nanometer1 ft = 304,800,000 nmFoot to Light Year1 ft = 3.2217e-17 lyFoot to Furlong1 ft = 0.001515 furFoot to Fathom1 ft = 0.1667 ftmFoot to Angstrom1 ft = 3,048,000,000 Å

Convert to feet

14 conversions
Meter to Foot1 m = 3.28084 ftKilometer to Foot1 km = 3,280.84 ftCentimeter to Foot1 cm = 0.03281 ftMillimeter to Foot1 mm = 0.003281 ftMile to Foot1 mi = 5,280 ftYard to Foot1 yd = 3 ftInch to Foot1 in = 0.08333 ftNautical Mile to Foot1 nmi = 6,076.12 ftMicrometer to Foot1 µm = 3.2808e-6 ftNanometer to Foot1 nm = 3.2808e-9 ftLight Year to Foot1 ly = 3.1039e16 ftFurlong to Foot1 fur = 660 ftFathom to Foot1 ftm = 6 ftAngstrom to Foot1 Å = 3.2808e-10 ft

Tips

  • 1 foot = 12 inches = 30.48 cm exactly. Knowing feet gives you inches instantly.
  • For a quick metric estimate, multiply feet by 0.3 — 10 ft ≈ 3 m.
  • Pilots and air-traffic control use feet globally, even over metric countries.

Common mistakes

  • Writing "6.2 ft" to mean "6 feet 2 inches" — the decimal form is 6.167 ft, not 6.2.
  • Confusing feet (length) with square feet (area) in US real-estate listings.
  • Using 0.3 instead of 0.3048 on structural drawings — errors accumulate on multi-storey buildings.

FAQ about the foot

What is a foot?
The foot equals 30.48 centimeters exactly and is one of the oldest length units in human history. It is the international aviation standard for altitude — commercial airliners cruise at 35,000 feet. In the US, building dimensions, human height and elevation are all expressed in feet. 1 foot = 12 inches.
Where is the foot used?
The foot is commonly used for: Aircraft cruising altitude in international aviation; US building heights, ceiling heights and room dimensions; Mountain elevations on global maps (Everest = 29,032 ft).
What is an example of a foot in real life?
Airliners cruise at 35,000 ft (10.7 km). Mount Everest is 29,032 ft (8,849 m). A standard US ceiling is 8 ft (2.44 m).
What category does the foot belong to?
The foot is a unit of length, part of the 15-unit length category on UnitConv.
How accurate are foot conversions?
All conversion factors follow NIST and BIPM international standards to 8 significant figures — the highest practical accuracy.
Explore all 15 length units and their conversions.📏 Length hub →