Definition
A navigation approximation stating that at a distance of 60 nautical miles, an angular error of one degree off course produces a lateral displacement of approximately one nautical mile. The rule allows pilots to estimate course corrections, off-track distances, and intercept angles using simple proportions rather than trigonometric calculations.
Plain English
A quick mental shortcut: if you fly 60 miles and end up one degree off course, you'll be about one mile to the side of where you wanted to be. Scale it up or down to estimate how far off track you are or how many degrees to turn to fix it.
Context Anchor
Used in navigation and flight-planning mental math, especially when estimating course error, correction angles, or descent path angles.
Derivation
Named for the number 60 because, in a circle, one degree of arc subtends roughly 1/60th of the radius. At 60 miles out, that geometry collapses neatly into a one-mile-per-degree relationship, making the math easy to do in your head.
Why Pilots Care
It lets pilots quickly calculate off-course distance and needed heading corrections without charts or calculators.
Analogy
Think of standing 60 miles from a straight road; each degree you turn your head moves your line of sight about one mile along the road.
Grounding Statement
Picture being 60 miles from a destination: each 1 degree your track is wrong puts you roughly 1 mile left or right of the intended path.
Intuition Check
Do not read “rule” here as a regulation. The Rule Of Sixty is a practical math shortcut, not a legal requirement.
Example Sentence 1
Halfway through the 60-mile leg, the pilot noted he was a mile south of course and used the rule of sixty to estimate a 2-degree heading correction.
Example Sentence 2
Applying the rule of sixty showed the crosswind required a ten-degree correction to stay on course.