BMX Jump Calculator

A BMX jump follows projectile motion physics once the rider leaves the ramp. Gravity pulls the rider down at 9.81 m/s² (32.2 ft/s²) while their horizontal velocity carries them forward. The ramp angle splits the exit speed into vertical and horizontal components.

Vertical component: v_y = v x sin(θ) Horizontal component: v_x = v x cos(θ)

From these, three key numbers follow:

Max height above the lip: h = v_y² / (2g) Air time (full flight): t = 2 x v_y / g Horizontal distance: d = v_x x t

A 45° ramp maximizes distance for a given speed, the classic range-maximizing angle from physics class. But BMX riders rarely use 45° because it also creates the most vertical clearance requirement and makes tricks harder to rotate. Real ramps typically run 30-40° for street and dirt, and 60-70° for vert.

Speed matters enormously. Doubling exit speed quadruples both height and distance, because both scale with v². Shaving even 5 mph off approach speed dramatically shortens the jump.

Landing lower than the lip

Most park and dirt jumps land below the takeoff, and the difference is not small. Dropping the landing by a metre extends the flight, so both the air time and the distance grow. The formula changes only in the last step: instead of solving for the ball returning to lip height, you solve for it reaching a point that much lower.

t = [v_y + √(v_y² + 2 × g × drop)] / g

Set the drop to zero and this collapses back to the flat-ground case, which is why the calculator below takes a drop figure and defaults it to zero. Measure it from the lip to the landing surface where you expect to touch down, not to the flat ground beyond.

What this leaves out

No wind and no air resistance. Wind against the jump cuts distance noticeably at speed, and a tailwind does the reverse. The rider’s body position matters too: tucked is faster through the air than spread out, though at BMX speeds drag is a small correction rather than a dominant term.

The bigger practical gap is that this is the path of a point mass. A bike and rider rotate, the wheels are not the centre of mass, and where the wheels touch down is not where the calculated point lands. Treat the distance as the middle of a landing zone, not a target.

Always assess jumps in person before riding. Terrain, ramp condition and approach speed vary far more than any formula suggests.