Wind & Runway
Reciprocal Runway Calculator
Reciprocal heading and the opposite runway designator in one step.
Inputs
°
Result
Reciprocal heading
270°
Opposite of 090°
Runway in use
09
Opposite runway
27
Reciprocal of 090° is 270° (RWY 09 ↔ 27)
Formula
Ref- Reciprocal = (heading + 180) mod 360
- Runway number = round(heading ÷ 10), 0 shown as 36
Worked example
RefIn use runway 09 (090°); what is the reciprocal?
- 1.Reciprocal heading = 090° + 180° = 270°.
- 2.Runway 09 ↔ runway 27.
Reciprocal 270°, opposite runway 27.
How it works
RefThe reciprocal is simply 180° away, and each runway is numbered by its magnetic heading rounded to the nearest ten. Quick reciprocal maths speeds up circuit joins, hold entries, and back-course tracking.
DGCA student tip
ExamThe ±200 trick: to add 180°, add 200 then subtract 20 (or vice-versa). 070° → 070 + 200 − 20 = 250°. Faster than long addition under pressure.
Common mistakes
Watch- Adding 180° but forgetting to wrap values over 360°.
- Reading runway 36 as 360 — the designator drops the trailing zero.
- Confusing the runway number (heading ÷ 10) with the full heading.