Pick the right shuttle speed.
Shuttle speed is calibrated by air density. Warmer or higher-altitude conditions = thinner air = shuttles fly farther, so you need a slower (lower-numbered) shuttle. Enter your ZIP and we'll suggest a speed.
How it works
speed = round( 77 − [ (T − 22) / 5 + A / 300 + (H − 50) / 50 ] ), clamped to 75–79
- Hot, humid, or high altitude → thinner air → shuttle flies farther → use a slower shuttle (75, 76).
- Cold, dry, or sea level → denser air → shuttle flies shorter → use a faster shuttle (78, 79).
- Each axis is independent: +5°C, +300m, or +50% RH each drops the speed by 1.
| Speed | Yonex label | When |
|---|---|---|
| 79 | Speed 4 | Cold gym, winter |
| 78 | Speed 3 | Cool indoor |
| 77 | Speed 2 (medium) | Standard tournament |
| 76 | Speed 1 | Warm conditions |
| 75 | Slow | Hot / humid / high-altitude (e.g. Denver, Mexico City, monsoon) |
Weather + altitude data via Open-Meteo (CC-BY-4.0). US ZIP lookup via Zippopotam.us.