Estimate mountain bike fork sag, shock sag, starting air pressure, rebound clicks, compression setting, travel use, bottom-out risk, and suspension tuning guidance. This MTB suspension calculator is useful for trail bikes, enduro bikes, downhill bikes, cross-country bikes, hardtails, e-MTBs, and bikepacking setups.
Sag setup:
The calculator multiplies fork and shock travel by your target sag percentage to estimate how much suspension should settle under your riding weight.
Air pressure:
If you enter current pressure and measured sag, the calculator estimates a pressure change needed to move closer to target sag.
Tuning guidance:
The result includes rebound, compression, setup status, bottom-out risk, and tuning notes based on bike type, terrain, and riding style.
A mountain biking suspension calculator helps find a good starting point before trail testing, especially when changing rider weight, terrain, bike setup, travel, pressure, or riding style.
Final suspension tuning depends on your bike’s leverage curve, shock tune, fork model, tire pressure, trail speed, terrain, temperature, volume spacers, damper design, and personal preference.
This calculator uses practical suspension setup estimates:
Target Sag = Suspension Travel × Sag Percentage
Many riders start around 20% fork sag and 25-30% shock sag for trail riding. XC usually uses less sag, while enduro and downhill often use more.
Slide the o-ring to the seal, sit or stand on the bike in riding position with gear on, carefully step off, then measure how far the o-ring moved.
Too much sag can make the bike feel soft, low, wallowy, or prone to bottoming out. Add air pressure or support if needed.
Too-slow rebound can make the suspension pack down over repeated bumps. Too-fast rebound can feel bouncy, uncontrolled, or unstable.