Work out sling angle load instantly with clear inputs, formula shown and shareable results.
Sling tension is the share of the load divided by the sine of the angle from the horizontal, so tension grows without limit as the slings flatten: at 30 degrees each leg carries twice its share. The cosine component squeezes the load horizontally, which can crush a fabricated item long before the slings themselves fail.
Leg tension
Tension = (load / number of legs) / sin(angle from horizontal)
Horizontal force
Squeeze = tension x cos(angle)
Preliminary estimate only. Lifting accessory selection must follow the manufacturer's rating tables and be planned by a competent person.
Tension = (load / number of legs) / sin(angle from horizontal). Sling tension is the share of the load divided by the sine of the angle from the horizontal, so tension grows without limit as the slings flatten: at 30 degrees each leg carries twice its share.
Standards generally set 30 degrees as an absolute minimum and recommend not less than 45, with 60 degrees preferred. Below 30 degrees the loads become unmanageable.
This calculator takes 3 inputs: Load mass, Number of sling legs, Sling angle from the horizontal. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.