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How to Calculate the Capacity of a Forklift

Tom Raley

Forklifts are designed to move a variety of cargo efficiently. These machines are the workhorses of the logistics chain and have evolved into very specialized pieces of equipment. While versatile and efficient, these machines do have limitations.

How to Calculate the Capacity of a Forklift

Exceeding these limitations can result in product damage, personal injury and even death.

  1. Determine the standard load capacity of your forklift. Each forklift will be rated at a certain capacity. The average sit-down model forklift will safely lift and carry 4,000 pounds. You can determine the standard capacity by examining the data plate located on the forklift. This data plate is your resource for all calculations regarding lift capacities for the forklift. The data plate should never be removed, replaced or altered in any manner.The data plate will normally be located in a very conspicuous position on the machine to allow easy access by the operator, normally from the operator's seat. You should never exceed the rated capacity of any forklift.

  2. Evaluate the load/cargo to be handled to determine its center of gravity (COG). On a standard forklift, the COG is based on a load center of 48 inches long and 48 inches tall. This would place the center of gravity 24 inches above the forks, and 24 inches from the backrest. If the load is titled forward, the COG moves forward. If the load is raised, the COG moves forward. If the mast is tilted back, the COG will move toward the forklift. As the COG moves, the load capacity will be altered. The 4,000 pound capacity of a standard forklift may be reduced by as much as 50% when the load is raised and tilted forward slightly. The data plate has a chart showing the decreasing load capacity as the load is raised.

  3. Calculate the load capacity by determining the weight of your load, the height the load will be raised, and the conditions involved in the movement. Will the load need to be titled? Will the load be shifted to one side? All of these have a direct relationship to the machines load capacity. On the data plate, find the COG of your load, then follow the line up to the height at which you plan to place the load. The weight listed where the cargo COG and height intersect is the load capacity of your forklift for those conditions. You should never attempt to add additional counter weight to the forklift in order to increase the load capacity, as this is highly dangerous and a violation of OSHA standards.

  4. Tip

    If the data plate has been damaged or removed, order a replaced from the manufacturer using the machines serial number to be certain to receive the proper replacement.


    All forklift operators should be trained in how to read a data plate and have a clear understand of the proper methods before being authorized to operate the forklift.