Rigging Sling Angle & Load Calculator
Plan two‑leg bridle lifts visually. Drag the hook and pick points, set weight, and the tool computes angle, per‑leg line tension, load share, and an optional D/d ratio check. Export a PNG lift snapshot.
Inputs
D/d ratio (optional)
Visual planner (two-leg bridle)
Drag the hook (circle) and the pick points on the load (squares). The math updates live.
Adjust the visual or enter angles, then select Calculate.
Method & assumptions
- Angles: Defined from the horizontal. Low angles increase line tension rapidly.
- Two-leg visual math: Solves per-leg tension using horizontal and vertical equilibrium with your geometry.
- Symmetric modes: Assume equal angles and equalized load share across the counted legs.
- Three/Four-leg note: For conservative planning, many crews assume only two legs carry the load. This mode reflects that assumption for tension estimates.
- D/d ratio: Displays your entered ratio only. Lower ratios increase bending stress; check manufacturer guidance for your sling type.
About this free rigging calculator
This free online rigging calculator helps you estimate sling angle, per‑leg line tension, and simple load sharing for common lifts. Use it as a sling angle calculator or two‑leg bridle calculator to visualize how moving the hook or widening pick points changes tension. You can also enter symmetric angles directly for quick checks on vertical, basket, choker, 3‑leg, and 4‑leg arrangements. The optional D/d ratio checker helps you document bend diameter versus sling diameter for your lift plan.
Rigging calculator FAQ
How do I read sling angle?
This tool uses degrees from horizontal. For example, 60 degrees is a steep sling; 30 degrees is shallow and produces much higher tension.
What is D/d ratio?
D/d is the ratio of the bend diameter around hardware to the sling diameter. Lower ratios increase bending stress. Always confirm acceptable limits with the sling manufacturer for your specific sling type and hitch.
Why do 3-leg and 4-leg estimates assume two legs share the load?
In real lifts, legs rarely share perfectly. A conservative planning practice is to assume only two legs carry most of the weight. This tool provides that option for quick estimation.
Can I export a lift snapshot?
Yes. Use Export PNG to save the canvas and key numbers for your documentation.