Truck weight & compliance glossary
Plain-English definitions of truck weight and load-compliance terms: GVW, GVWR, GCW, axle weight, the Bridge Formula, tandem, tridem, KPRA, tare, payload and more.
Plain-English definitions of the terms behind axle-weight compliance. Each links to a fuller explanation; the calculators are in free tools.
Axle weightLoad carried by one axle or axle group.
Gross vehicle weight (GVW)Total actual weight of a loaded vehicle.
GVWRManufacturer's maximum rated weight.
Gross combination weight (GCW)Tractor plus trailer plus load.
Federal Bridge FormulaWeight allowed by axle spacing.
Tandem axleTwo axles close together as a group.
Tridem axleThree-axle group (common in Canada).
Steer axleThe front, steered axle.
Kingpin to rear axle (KPRA)Length rule behind California 40-ft limits.
Center of gravity (CoG)Where a load's weight balances.
Tare weightEmpty weight of the vehicle.
PayloadWeight of the cargo you can carry.
Check a real load in secondsLoadLegit turns axle weights into a pass/fail compliance verdict — federal Bridge Formula plus verified state and Canadian rules — and issues a shareable certificate. Try it free →
Related
Free trucking compliance toolsFree calculators for truckers and dispatchers: the Federal Bridge Formula, axle weight limits, and weight/length unit conversion. No login, no signup.Federal Bridge Formula calculatorFree Federal Bridge Formula calculator. Enter axle count and the spacing between the extreme axles to get the maximum legal weight (W = 500(LN/(N-1)+12N+36)).