Calculate the actuator force a scissor lift needs to raise a load from the payload, platform and arm masses and the arm angle, in N, kN, lbf or kgf.

Single-stage X lift with a horizontal actuator moving the full base width. Platform and arm masses are optional.

Angle between an arm and the base; force rises sharply at low angles.

Default 1.5 is an illustrative margin, not a certified safety factor. Enter 1 for the bare theoretical force.

Platform and arms (blank = 0)

Uniform arm mass is modeled at half the platform height.

Scissor Lift Force Formula

The following ideal static equation applies to a single-stage symmetric X with centered loading and a horizontal actuator whose stroke changes the full lower-endpoint separation (base width). Uniform moving arms have their centers of mass at half the platform height. Different mounts, half-width strokes, nonuniform masses, friction, dynamic loads and additional stages require their own analysis.

Fideal = (WP+WT+(WA/2)) / (tan(a))
  • Fideal is the ideal input force for this full-base-width actuator coordinate; all W terms are weights in consistent force units.
  • WP is the payload weight (force), and WT is the platform weight (force).
  • WA is the combined weight (force) of the uniform moving scissor arms. Their centers of mass rise by half the platform displacement, producing the WA/2 virtual-work contribution.
  • a is the angle between the arms and the ground (use degrees or radians consistently with the tangent function)

The effective vertical load is payload weight + platform weight + half the combined uniform moving-arm weight. Divide it by tan(a) for the ideal full-base-width input force. In force mode, enter this already-effective load; no extra arm or platform weight is added. A chosen multiplier scales the ideal result arithmetically and does not establish adequate strength, stability, rated capacity or safe operation.

What is a Scissor Lift Force?

Definition:

A scissor lift is a lifting mechanism that raises and lowers a platform (and its load) vertically using linked, folding supports arranged in an “X” pattern. The scissor lift force is the input/actuator force required to raise the platform at a given arm angle; in real equipment it depends on the lift geometry (cylinder/screw placement, number of stages), friction, and load distribution. Scissor lifts are commonly powered by hydraulic cylinders or electric screw/drive systems, and some designs use pneumatic actuation.

How to Calculate Scissor Lift Force?

Example Problem:

The following example outlines the steps and information needed to calculate Scissor Lift Force.

First, determine the payload weight: 50 lbf in this example. The platform weight is zero, and the theoretical example uses multiplier 1.

Next, determine the weight of the scissor arms. These are measured to be 50 lbf.

Next, determine the angle between the arms and the ground. This is measured to be 20 degrees.

Finally, calculate the scissor lift force using the formula above:

Fideal = (WP + WT + (WA/2)) / tan(a)

Fideal = (50 + 0 + (50/2)) / tan(20°)

Fideal ≈ 206.06 lbf. With the calculator’s illustrative chosen multiplier 1.5, the scaled result is approximately 309.09 lbf. The default is not a recommended design or safety factor.