How wind components are calculated
The calculator normalizes the angular difference between the wind-from direction and runway direction to the shortest signed angle. Crosswind is wind speed multiplied by the sine of that angle; the along-runway component is wind speed multiplied by its cosine. A positive along-runway value is reported as headwind and a negative value as tailwind.
Use matching directions and units
Use the runway direction for the actual takeoff or landing direction, not the reciprocal end. Wind-from direction and runway heading must use the same north reference. Tower-reported wind in the United States is magnetic, while other weather sources may report true direction. Runway designators approximate magnetic azimuth rounded to the nearest ten degrees, so a published runway heading can be more precise. All wind, gust, and comparison speeds must use the selected speed unit.
Do not treat this as an operating approval
The trigonometry does not decide whether an operation is safe or permitted. Aircraft capability, demonstrated crosswind information, approved limitations, operator procedures, pilot proficiency, runway contamination and braking, gusts, wind variability, obstacles, and current airport conditions all matter. The optional comparison fields accept user-entered values only; verify them against the applicable aircraft documents and operating rules, and use official current weather and airport information.