Sling Tension — Single Vertical Sling
Per-leg tension for a single vertical sling from load, sling angle and hitch efficiency.
The reference case every tag rating quotes — straight pull, full WLL. Its real-world failure mode isn't tension arithmetic but the load rotating: a single point of suspension gives the load freedom to spin, and a tagline becomes part of the rigging plan.
Formula
Note: Rigging and crane decisions are life-safety critical. This calculator is a planning aid — the load chart, sling tags, site lift plan and a qualified lift director govern every real lift.
Per-leg tension for a single vertical sling from load, sling angle and hitch efficiency. A free crane load, wind & rigging safety tool — no sign-up, no upload, instant results in your browser.
About Sling Tension — Single Vertical Sling
Sling Tension — Single Vertical Sling computes the governing relationship T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency live as you type. The reference case every tag rating quotes — straight pull, full WLL. Its real-world failure mode isn't tension arithmetic but the load rotating: a single point of suspension gives the load freedom to spin, and a tagline becomes part of the rigging plan. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Sling Tension — Single Vertical Sling
- 1Enter your values — Load weight, Sling angle from horizontal, Load-bearing legs, Hitch efficiency (sensible defaults are pre-filled).
- 2Read the live results: Tension per leg, Min sling WLL per leg, Angle multiplier.
- 3Check the "with your numbers" line to see T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Sling Tension — Single Vertical Sling?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency with authoritative sources cited on the page (ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; Wire Rope Technical Board — Wire Rope Users Manual, 4th ed.)
- ✓The reference case every tag rating quotes — straight pull, full WLL.
- ✓SI ⇄ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the sling tension — single vertical sling use?+
It evaluates T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency, exactly as published. Sources: ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; Wire Rope Technical Board — Wire Rope Users Manual, 4th ed.. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
The reference case every tag rating quotes — straight pull, full WLL. Rigging and crane decisions are life-safety critical. This calculator is a planning aid — the load chart, sling tags, site lift plan and a qualified lift director govern every real lift.
When is this calculator the right tool for the job?+
Per-leg tension for a single vertical sling from load, sling angle and hitch efficiency. A free crane load, wind & rigging safety tool. Its real-world failure mode isn't tension arithmetic but the load rotating: a single point of suspension gives the load freedom to spin, and a tagline becomes part of the rigging plan. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes — the SI ⇄ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
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