Weight Distribution Hitch & FALR Load Transfer Calculator
Calculate dynamic axle weight transfer, spring bar tension, and Front Axle Load Restoration (FALR 50%–100%) according to SAE J2807 standards for travel trailers and heavy towing rigs.
Tow Vehicle & Trailer Geometry
lbs
Deadweight on hitch ball.
Inches
Front axle to rear axle center.
Inches
Rear axle center to hitch ball.
Inches
Hitch ball to trailer axle center.
Front Fender Height Measurements (SAE J2807 FALR Audit)
in
in
in
Measure ground to front wheel arch center.
Front Axle Restoration (FALR)
50.0% FALR (OPTIMAL)
50.0%
SAE J2807 recommends 50% to 100% restoration. Steering authority restored.
Front Axle Shift (Unhitched vs WDH)
-171 lbs
Without WDH: -341 lbs lift
Rear Axle Shift (Unhitched vs WDH)
+845 lbs
WDH relieves 396 lbs from rear
Trailer Axle Transfer & Hitch Torque
Weight Transferred to Trailer Axles:
+112 lbs
Estimated Spring Bar Applied Torque:
2,060 lb-ft