Course Wind Component Calculator (Head/Tail + Cross)
Split any forecast wind over your course into the headwind that costs time and the crosswind that demands crab — the two numbers every leg brief needs.
The headwind component feeds the GS, time and fuel math; the crosswind component feeds the crab via max-drift. Splitting the wind once per leg replaces a fistful of separate guesses.
Formula
⚠️ For flight planning and education only — verify with official sources and certified equipment. Not for primary navigation.
Split any forecast wind over your course into the headwind that costs time and the crosswind that demands crab — the two numbers every leg brief needs.
About Course Wind Component Calculator (Head/Tail + Cross)
A forecast wind is one arrow but two taxes: the along-course component that sets your ground speed (and therefore time and fuel), and the cross-course component that sets your crab. This calculator resolves any wind against any course into both, names the side the crosswind comes from, and reports the wind angle — the geometry brief that should precede every leg's heading and fuel arithmetic.
How to use Course Wind Component Calculator (Head/Tail + Cross)
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula head = W·cos(Δ); cross = W·sin(Δ); Δ = wind direction − course substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Course Wind Component Calculator (Head/Tail + Cross)?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula head = W·cos(Δ); cross = W·sin(Δ); Δ = wind direction − course with sources cited on the page
- ✓The headwind component feeds the GS, time and fuel math; the crosswind component feeds the crab via max-drift. Splitting the wind once per leg replaces a fistful of separate guesses.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
How is this different from the runway crosswind calculator?+
Same trigonometry, different reference and consequence: against a runway, the components govern controllability at touchdown; against a course, they govern cruise economics (headwind) and heading (crosswind). Planning runs this tool per leg with winds-aloft; the runway version runs at both ends with surface winds. Two tools because the decisions differ, not the math.
Which component do I feed into the time and fuel numbers?+
Only the head/tail component adjusts ground speed: GS ≈ TAS − headwind (the crab's cosine cost is under 1% for normal angles). The crosswind component never slows you directly — it only sets the crab via max-drift — which is why a pure 30-kt crosswind leaves your ETA almost untouched while demanding 15° of heading.
What's the fastest mental version of this split?+
The clock code both ways: wind 30° off the course gives half as crosswind, ~90% (call it 'almost all') as headwind; 45° gives ¾ and ¾; 60° gives all and half. Anchor the two extremes — straight ahead is all-head/no-cross, abeam is the reverse — and the middle interpolates itself within a couple of knots.
Should I use the component breakdown when choosing altitude?+
Yes — winds-aloft tables differ per level, and only the along-course component matters for the time/fuel decision. A 35-kt wind at 9,000 that's 80° off course is a 6-kt headwind; a 25-kt wind at 7,000 dead on the nose is a 25-kt one. Splitting each level's forecast against your course finds the genuinely faster altitude, which raw wind speeds disguise.
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