Boxing the compass

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (September 2009)

A 16-point compass rose

A 32-point compass rose

A historical compass card

Boxing the compass is the action of naming all thirty-two principal points of the compass in clockwise order. Such names, formed by the initials of the cardinal directions and their intermediate ordinal directions, are accepted internationally, even though they have their origin in the English language, and are very handy to refer to a heading (or course or azimuth) in a general or colloquial fashion, without having to resort to computing or recalling degrees.

The set of 32 named points can be further divided into a set of 128 named directions using quarter-points,^[1] although for communicating heading these fractional points have been superseded by degrees measured clockwise from North.

Compass points

A simple algorithm can be used to convert a heading to an approximate compass point:

1. Divide the heading in degrees by 11.25 (360/32) to get to the case of 32 named points.
2. Add 1.5 to center the named points in their respective sectors on the circle, since north is 1 in the table instead of 0. If the result is 33 or more, subtract 32 to keep within the 32-point set.
3. Now look up the integer part of the result in the table below.

For example:

A heading of 75°, divided by 11.25 gives 6.67, added to 1.5 gives 8.17, truncated to give 8. 8 in the table below corresponds to east by north.

See also

• Heading (disambiguation)
• Course (navigation)
• Bearing (navigation)
• Navigation
• Cardinal direction
• Ordinal direction
• Compass rose
• Wind rose

References

External links

• Wind Rose – discusses the origins of the names for compass directions.
• Compass Rose – Actual Compass Roses for the Home.