Definition
A value or time given as a calculated forecast rather than a confirmed fact. In ATC and flight planning, EST appears next to a time, position, or altitude to indicate that the figure is the pilot's or controller's best computed prediction, not an observed or actual value.
Plain English
A best-guess number based on calculation. It is what the pilot or controller expects, not what has already happened.
Context Anchor
Seen in FAA material, flight planning, airport information, and operational notes when a time or value is expected but not yet confirmed.
Derivation
From the Latin aestimare, meaning to value or appraise. The aviation use keeps that sense of working out a value from the information available, rather than measuring it directly.
Why Pilots Care
Knowing a time or position is estimated lets pilots adjust fuel planning, arrival expectations, and coordination with air traffic control without assuming the figure is fixed.
Intuition Check
Estimated does not mean confirmed. If you see EST, treat the information as a calculated best guess until an actual or confirmed value is available.
Example Sentence 1
Cleveland Center, Cessna Three Four Tango, estimating BRAVO intersection at one five.
Example Sentence 2
ATC reported an EST ten-minute delay for sequencing into the arrival stream.