Tools for checking your own working. Each calculator shows its inputs, the
intermediate steps and the formula used.
These are check aids. They do not replace the lift plan, the manufacturer’s
data, the applicable standard or a competent person’s judgement. Always work to the marked WLL
of the equipment you are actually using.
Sling leg tension
Sling leg tension
As the angle between the legs widens, the tension in each leg rises above a simple share of the load. This is the calculation people most often get wrong by eye.
Check aid only. This calculator is for verifying your own working. It does not replace the lifting plan, the equipment manufacturer's data, the applicable standard, or a competent person's judgement. Always work to the marked WLL of the actual equipment.
Centre of gravity — two lifting points
Centre of gravity — two lifting points
For a load slung from two points, work out how the mass divides between them. An off-centre CoG loads one leg far more than the other, and the load will swing as it leaves the ground.
Check aid only. This calculator is for verifying your own working. It does not replace the lifting plan, the equipment manufacturer's data, the applicable standard, or a competent person's judgement. Always work to the marked WLL of the actual equipment.
Round sling colour codes (EN 1492-2)
| Colour | WLL (vertical lift) |
|---|---|
| Violet | 1 t |
| Green | 2 t |
| Yellow | 3 t |
| Grey | 4 t |
| Red | 5 t |
| Brown | 6 t |
| Blue | 8 t |
| Orange | 10 t |
Read the label, not just the colour. The colour code applies to polyester round slings under EN 1492-2 and gives the WLL for a straight vertical lift. Choke and basket hitches, and any leg angle, change the permissible load. A sling whose label is missing or unreadable must be taken out of service regardless of its colour.