Name the support points
Set A as the left reference and B as the second lifting point. Both reactions must act vertically in this model.
LIFTING & RIGGING / TOOL 09
Two Lifting Point Load Distribution Calculator
Use this to calculate how an offset centre of gravity divides a rigid load’s vertical weight between two lifting points.
Before you start: required inputs
- Obtain the complete mass and the load’s verified centre of gravity.
- On a side elevation, measure the horizontal distance between points A and B and the CG distance from A toward B.
Calculation diagram
A PRACTICAL WALKTHROUGH
How to use this calculator
Locate the CG between them
Enter the point spacing and the CG position from A. The CG must lie within the interval from A to B.
Use the separate reactions
Read the vertical force and percentage at each lifting point. Do not assume equal sharing unless the CG is at the midpoint.
10,000 kg load with CG nearer point A
THE INPUTS
Mass 10,000 kg; point spacing 4 m; CG 1.5 m from A toward B.
THE RESULT
Point A carries 62.5%, or 61.2916 kN. Point B carries 37.5%, or 36.7749 kN. The point closer to the CG carries more vertical load.
What does the result mean?
01
The two vertical reactions sum to the static weight of the entered mass.
02
The percentage outputs express load sharing, while kN outputs express vertical forces at the lifting points.
03
Inclined sling tension is not the same as the reported vertical reaction; the sling angle must be considered separately.
Watch for this
Using the distance from the load’s outside edge instead of the distance from point A, or treating the two points as equally loaded despite an offset CG.
Formula & model conditions +
Reaction A = W × (spacing − CG distance) / spacing
Reaction B = W × CG distance / spacing
- The load is rigid and supported by exactly two vertical reactions in one vertical plane.
- The centre of gravity must be between the two lifting points. Dynamic effects, flexibility and load tilt are excluded.
- If slings are inclined, calculated vertical reactions must be resolved into sling forces separately.
Common questions
What happens if the CG is at a lifting point?
The other point has zero calculated vertical reaction. The tool reports this and flags the need to check stability and the actual lifting arrangement.
Can I use this for two cranes lifting one load?
It can show ideal static vertical shares for a rigid two-support model, but it does not plan a tandem lift or account for crane motion, flexibility and dynamic redistribution.