Definition
A simple unit conversion used to translate aircraft or wind speed from knots (nautical miles per hour) to statute miles per hour (mph). One knot equals approximately 1.15 mph, so multiplying a speed in knots by 1.15 gives the equivalent speed in mph. The reverse conversion (mph to knots) uses a factor of approximately 0.87.
Plain English
Knots and miles per hour are two ways of measuring speed. To change knots into miles per hour, multiply the knots figure by about 1.15. So 100 knots is roughly 115 mph.
Context Anchor
Seen when comparing aviation speeds, winds, or aircraft performance figures with speeds written in everyday miles per hour.
Derivation
A knot is one nautical mile per hour. A nautical mile (about 6,076 feet) is longer than a statute mile (5,280 feet), which is why one knot is slightly faster than one mph. The conversion factor 1.15 simply reflects that ratio between the two types of mile.
Why Pilots Care
Ensures correct interpretation of speeds from mixed sources such as foreign data or surface reports to avoid misjudging distances or times.
Grounding Statement
If an aircraft speed is given in knots and you want the familiar miles-per-hour value, multiply by about 1.15.
Intuition Check
A knot is not the same as a mile per hour. Knots use nautical miles; miles per hour use ordinary road miles.
Example Sentence 1
The aircraft was cruising at 120 knots, which works out to about 138 mph after converting knots to miles per hour.
Example Sentence 2
During cross-country planning the student converted cruise speed from knots to miles per hour to match the sectional chart scale.