What is Projected 40 (P40)?

The P40 metric is calculated from two stride cycle measurements:

• Stride length (toe-to-toe distance at max extension, normalized by your leg length)

• Cadence (foot contacts per second at max velocity)

Combined: `speed = stride_length × cadence × 2`, then `P40 = 36.576m / speed`.

For accurate P40, we need:

1. Your height — enter it in Settings

1. Side-view video — P40 requires accurate stride length measurement

1. At least 3 stride cycles visible in the video

What's a good P40? Varies hugely by sport, age, and level. Track your own P40 over time — improvement is what matters.