常规数据表中显示的容量根据车辆的额定容量在500mm至1200mm的负载中心处给出。当要处理更长的负载时，以下所示的计算仅可用于替代负载中心的车辆容量的指导。

• Q =标称额定容量（负载重量）*

• C =额定载荷中心

• C2 =新的负载中心

• Q2 =新的剩余容量

• X =轴心至前叉面

Q2 = Qx /（x + C）

随着负载中心的增加，额定容量会降低。这种估算方法仅与车辆的前进力矩有关（对于有伸手的前伸车辆），仅作为指导。*此数字可能会随着电梯高度的增加而减少。
因此，不能在小于引用的负载中心处处理更大的重量；在高空航行时，情况可能受其他因素制约。还必须考虑货叉压力以及桅杆和滚筒上的压力。可能需要咨询以确保正确评估车辆的能力以应对异常装载情况。
如果要在叉车上安装附件，叉车的额定容量将会降低。

Capacities shown in conventional data sheets are quoted at between 500mm and 1200 mm load centres depending on truck rated capacity. When longer loads are to be handled, the calculation shown below may be used as a guide only for truck capacity at alternative load centres.

• Q = nominal rated capacity (load weight)*

• C = rated load centre

• C2 = new load centre

• Q2 = new residual capacity

• X = axle centre to fork face

Q2= Qx / (x+C)

Rated capacity is reduced as the load centre is increased. This method of estimating relates only to forward moments of the truck (and for a reach truck with reach out), and serves as a guide only. * This figure may reduce as lift height increases.
It does not follow that greater weight can be handled at load centres less than quoted; and at high lift the situation may be governed by other factors. Fork stress, and stress on mast and rollers, must also be taken into account. Consultation may be necessary to ensure that your truck capacity is correctly assessed for unusual loading conditions.
Where an attachment is to be fitted to a fork lift truck, the nominal capacity of the truck will be reduced.