Why are runways numbered the way they are?

Plainly put, airport runways are numbered according to compass bearings. This means runway numbers are based on the compass with 360 representing north, 90 representing east, 180 representing south, and 270 representing west. Runways are numbered between 01 and 36.



Runway numbers are based on the magnetic heading of the runway, which is the direction it faces on a compass. The full compass heading (0° to 360°) is rounded to the nearest 10 degrees, and the final zero is dropped to create a two-digit number. For example, if a runway points east at a 90° heading, it is labeled Runway 09. Because every runway can be used in two directions, the number on the opposite end is always 180° away; thus, Runway 09 is Runway 27 at the other end. In 2026, you may notice that some runway numbers are changing globally. This is due to magnetic drift, where the Earth's magnetic north pole shifts over time, occasionally requiring airports to repaint their numbers to stay accurate for pilots. If an airport has parallel runways, they add letters like L (Left), R (Right), and C (Center) to distinguish them (e.g., 25L and 25R).

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A: The runway number is the approximate magnetic heading. As an example, runway 35 is pointing approximately 350 degrees magnetic. The opposite end of the runway is 17 or approximately 170 degrees magnetic.

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As Atlas Obscura explains, the numbers that runways have aren't arbitrary. A runway always has a number between 1 and 36, and that number isn't just the runway's nickname, but also indicates how many degrees away that runway is from magnetic north, rounded to the tens.

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Runway numbers are determined by rounding the compass bearing of one runway end to the nearest 10 degrees and truncating the last digit, meaning runways are numbered from 1 to 36—as per the diagram below. The opposite end of the runway always differs by 180 degrees, so it's numbered 18 higher or lower.

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Runways will be numbered based on their position so 06/24 means one end of our runway is 60 degrees, the opposite end is 240 degrees – so 180 degrees, also known as a straight line!

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Larger airports usually have several runways in different directions, so that one can be selected that is most nearly aligned with the wind. Airports with one runway are often constructed to be aligned with the prevailing wind.

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The airfield is managed by three FAA air traffic control towers. O'Hare has a voluntary nighttime (22:00–07:00) noise abatement program. Currently, O'Hare has the most runways of any civilian airport in the world, totaling eight.

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Weather, in particular wind speed and direction, is usually the main reason for selecting which runways are used at an airport, the direction aircraft take-off and land, and the flight paths that are used.

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All runways are numbered. The number used corresponds to the magnetic direction of that runway when landing or taking off on it. The runway number is abbreviated and missing the last digit. As an example. If you are landing or taking off on runway 20, it is actually 200°

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In addition, runway numbers are connected to the direction a plane is traveling—so while on a handheld compass, south corresponds to 180 degrees, or 18 in runway terms, if a plane is on runway 18–36, then it's heading north, according to the designation on a compass with the runway overlay (see image below, courtesy of ...

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Runway 36 is the entire runway, with traffic moving to the north (i.e. facing about 360 degrees, magnetic). Runway 18 is the same north/south strip of pavement, with traffic moving to the south (i.e. facing about 180 degrees). If you're lined up ON runway 36, you're at the south end of it, facing north.

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Shigatse Peace Airport, China (runway length: 5,000m) Shigatse Peace Airport (RKZ), a dual-use military and civilian airport in Shigatse, Tibet hosts the longest runway in the world. The new runway (09/27) stretches 5,000m (16,404 ft) long with a 60-meter asphalt overrun at each end.

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A runway should be marked according to its usage. The three classifications of runways are Visual Runways, Nonprecision Instrument Runways, and Precision Instrument Runways.

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So what do these numbers on runways mean? The numbers on the runway, officially known as designators, indicate the runway heading, always in magnetic degrees and rounded to the nearest ten. So, if the magnetic bearing is 73º, the runway will be designated with the numbers 07.

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The runway edge lights are white, except on instrument runways yellow replaces white on the last 2,000 feet or half the runway length, whichever is less, to form a caution zone for landings.

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For example, Runway 9-27 is oriented east-west. You might be thinking that the numbers on this diagram are backwards. On a handheld compass, south is 180 degrees (so 18 in runway terms) and west is 270 (27). But the “W” is numbered 9 because the runway number is connected to the direction the plane is traveling.

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