The Truck Weight Calculator provides a convenient way to determine the maximum legal weight that any set of axles on a vehicle/vehicle combination may carry on ND interstate and state highways. The allowable weight on a vehicle/vehicle combination may increase by either adding additional axles or by increasing the distance between axles. The formula for the calculator is a weight-to-length ratio. This formula was enacted by Congress and the State to limit the weight-to-length of a vehicle crossing a bridge.
The formula is
W = 500 [LN/N-1 + 12N + 36]
W = Maximum weight in pounds on any group of two or more axles.
L = Distance in feet between extremes of any group of two or more consecutive axles.
N = Number of axles in the group under consideration.
Information needed when using ND Truck Weight Calculator:
- Highway type - State, Interstate, 129000lbs Primary
- Total # of Axles (including steering axle)
- Number of tires per axle
- Tire Width (found on tire sidewall)
- Bridge Length (distance from axle center to consecutive axle center)
- Steering axle rating (needed for interstate highway)
The legal gross vehicle weight (GVW) on ND state highways is 105,500 pounds unless otherwise posted. On all other highways the maximum GVW is 80,000 pounds unless designated for more, not to exceed 105,500 pounds. All tire and axle weights must be legal. No tire shall exceed 550 pounds per inch of tire width.
The legal GVW on the interstate highway system is 80,000 pounds. An interstate permit is required when a
vehicle hauling a reducible load exceeds 80,000 pounds GVW. The GVW shall not exceed 105,500 pounds.
The vehicle combination must have sufficient axles and bridge lengths. All tire and axle weights must be legal.
No tire shall exceed 550 pounds per inch of tire width, except on the steering axle. The weight on the
steering axle shall be determined by the manufacturer’s
axle rating
and shall not
exceed 20,000 pounds. For more information on the interstate permit visit the
NDHP Motor Carrier website.
On the primary network system, a vehicle with sufficient number of axles and bridge lengths can exceed 105,500 pounds
gross vehicle weight. A primary network permit is required. The gross vehicle weight shall not exceed 129,000 pounds.
The vehicle must comply with the inner and outer bridge length limits of the federal bridge formula.
All tire and axle weights must be legal. No tire shall exceed 550 pounds per inch of tire width.
To view the designated primary network highways visit https://www.nd.gov/ndhp/motor-carrier/permit-policies.
To obtain a permit visit https://www.nd.gov/ndhp/motor-carrier-operations/e-permits.