MXFree jump calculator
Stop guessing.Build it right.
Real physics, real construction specs. Know exactly where you'll land, and how hard, before a single shovel hits the dirt.
Double · Tabletop · Step-up · Step-down · free, no account needed
Design your jump
Adjust the sliders: the profile, trajectory, and every spec update instantly. Hit Test ride to watch the jump at your speed.
Takeoff
ft
Beginner 1–3 ft · Intermediate 3–6 ft · Advanced 6–10 ft
°
The face at the lip, where the bike leaves. Beginner 10–16° · Intermediate 16–22° · Advanced 22–30°
ft
The curve that lifts the face off the ground. Tighter kicks harder.
Gap & landing
ft
Beginner 5–20 ft · Intermediate 20–40 ft · Pro 40–70 ft
ft
Negative = lower landing · positive = higher landing
°
Match or run slightly shallower than takeoff for soft landings
ft
The curve at the bottom of the landing into flat. Tighter bottoms out harder.
Rider & build width
mph
Backyard 10–35 mph · Track 35–55 mph
ft
Used for the dirt volume estimate only
Peak height
—
ft above lip
Distance flown
—
ft from lip
Air time
—
seconds
Landing impact
—
—equivalent flat drop
Speed safety window
—
Takeoff
—
yd³
Landing
—
yd³
Total dirt
—
yd³
Saved jumps
From slider to shovel
Set your jump shape
Choose double, tabletop, step-up, or step-down. Dial in lip height, lip angle, the transition that curves the face up off the ground, gap distance, landing slope, and the curve at the bottom of the landing. The profile redraws in real time, drawn to true scale.
Verify the trajectory
The orange arc shows exactly where a rider travels at your speed, and the crosshair marks the true impact point on the landing surface. Hit Test ride to watch it happen.
Check speed and impact
The gauge shows the speed window where the rider clears the knuckle but stays on the downslope. The impact rating tells you how hard the landing hits, like dropping flat from that many feet.
Print and build
Print the spec sheet: a full construction document with the profile diagram, stake placements, slopes, dirt volumes, and the safe speed range. Take it to the site.
Built-in safety checks
Every output is designed to help you make better decisions before any dirt moves.
Smooth transitions, no kickers
A real face leaves the ground on a curve and finishes straight at the lip angle. You set the curve's radius; the calculator shows the load it puts on the rider at your speed and flags a transition tight enough to kick, one of the leading causes of crashes on home-built jumps.
Impact rating
Landing on a matched downslope absorbs most of the fall. The equivalent-flat-drop number shows how hard each landing really is, so you can shape the landing before anyone tests it.
Safe speed window
Every jump shape has a speed range: enough to clear the knuckle, not so much that you overshoot the toe. The gauge shows exactly what this jump was designed for.
Always verify on site
This tool assumes flat ground and clean projectile physics: no wind, no drag, no suspension. Real terrain, soil, and technique all matter. Verify on site and always roll it slow first.
Building more than one jump?
MX Track Builder is this calculator's big brother: plan the whole track, from layout and flow to every jump on it.
Try MX Track Builder ↗