About

Aviation altitude is predominantly measured in feet worldwide, a standard solidified by the dominance of US and British aviation in the mid-20th century. However, vast regions including China, Russia (until 2011/2017), and North Korea utilize the Metric System (meters) for flight level assignment. Pilots traversing these Flight Information Regions (FIRs) must accurately convert altitude assignments to avoid vertical separation infringements.

This tool converts between Feet, Meters, and Flight Levels (FL). A Flight Level is simply an altitude in hundreds of feet based on standard pressure (1013.25 hPa). For example, FL350 is nominally 35,000 feet. Precision is critical; Reduced Vertical Separation Minima (RVSM) allows for only 1,000 feet (approx 300 meters) between aircraft.

Formulas

The core conversion relies on the definition of the foot:

1 ft = 0.3048 m

To calculate Flight Level from Meters (approximate):

FL ≈ Altitude_m0.3048 ÷ 100

Reference Data

Flight Level (FL)	Feet (ft)	Meters (m)	Metric Assignment (China)
FL100	10,000	3,048	3,000 m
FL130	13,000	3,962	4,000 m
FL190	19,000	5,791	6,000 m
FL260	26,000	7,925	8,000 m (RVSM entry)
FL290	29,000	8,839	8,900 m
FL310	31,000	9,449	9,500 m
FL350	35,000	10,668	10,700 m
FL390	39,000	11,887	11,900 m
FL410	41,000	12,497	12,500 m
FL510	51,000	15,545	15,500 m

Frequently Asked Questions

Altitude is the vertical distance above mean sea level (MSL), corrected for local pressure variations (QNH). Flight Level (FL) is the vertical distance above the standard pressure datum of 1013.25 hPa (29.92 inHg), regardless of the actual sea level pressure. FL is used above the Transition Altitude.

These nations historically adopted the metric system for all scientific and transport standards. While Russia has largely moved to RVSM feet-based levels for international compatibility, China maintains a metric RVSM system (RVSM-Metric), requiring pilots to fly specific metric altitudes that do not perfectly align with standard FLs.

In navigation computers, conversions are precise. However, for pilot mental math, rough approximations (1 m ~ 3.3 ft) can be dangerous near airspace boundaries. Always use approved conversion tables or avionics data.

QFE is a pressure setting that sets the altimeter to read zero when on the runway. Some military and Eastern bloc procedures use QFE for landing, meaning the altimeter reads height above ground (AGL) rather than altitude above sea level (MSL). This requires careful conversion if the pilot is used to QNH.