Crosswind & Density Altitude
LiveWind components & runway pick
On the App Store as “Crosswind & Density Altitude”
Free web tool
How do you calculate crosswind and headwind components for a runway?
Take the angle between the wind and the runway heading — Δ = wind direction − (runway number × 10°) — then the headwind is wind speed × cos Δ and the crosswind is wind speed × sin Δ. A 300° wind at 20 kt on runway 27 (270°) works out to a 17-kt headwind and a 10-kt crosswind from the right; the sign of sin Δ tells you the side, and a negative headwind is a tailwind. For density altitude, first find pressure altitude (field elevation + (29.92 − altimeter in inHg) × 1,000), then add about 118.8 ft for every °C the outside air runs above the standard-atmosphere temperature at that altitude.
Wind (blowing FROM)
Crosswind (steady)
9 kt
Blowing from the RIGHT
Headwind
16 kt
Component along the runway
Crosswind in the gust
13 kt
Peak from the RIGHT · gust factor 8 kt
Best runway into this wind
RWY 30
0 kt crosswind · 18 kt headwind
Crosswind is within 80% of your 15 kt limit.
Wind triangle: headwind = wind × cos Δ, crosswind = wind × sin Δ, where Δ is the wind direction minus the runway heading. Density altitude uses the standard atmosphere (PA = elevation + (29.92 − altimeter) × 1,000; ISA = 15 °C − 1.98 °C per 1,000 ft; DA = PA + 118.8 ft per °C above ISA). Same computed engine as the app.
Training and planning aid only — not for primary flight operations. It computes and compares against limits you set; it never advises. Always verify wind, weather, and aircraft performance with official sources and your aircraft's POH.
Take it with you
The full Crosswind & Density Altitude app adds a live compass rose, steady-and-gust crosswind graded against your own personal minimums, a best-runway table across all 36 headings, and °C/°F and inHg/hPa toggles — all one-tap and fully offline in the run-up area.
What it is
A one-screen preflight calculator for student and general-aviation pilots. Pick your runway, dial in the reported wind, and read the two numbers that decide the flight: headwind and crosswind, for both steady wind and gust, on a compass rose that updates as you turn the wheels.
Why we built it
Full electronic flight computers cost $9.99 and up and bury these everyday answers under fifty other functions; the cheap single-purpose apps are stale and have no drawn rose. This sits in the gap at $2.99 with exactly the preflight math a pilot uses every flight, grades every result against the pilot's own personal minimums, and adds a density-altitude read for hot-and-high days.
Want one like this?
Crosswind & Density Altitude is one of 92. We can build yours.
Every app on the shelf started as one honest problem, scoped small and built native, end to end. That’s exactly how we approach client work — designed, built and shipped, without the bloat.
