Spreader Beam Calculator
Bending in a lifting spreader and the section it needs.
A 'spreader' with slings to a central hook is actually a lifting BEAM in bending — design it as one (this tool), or rig it as a true compression spreader with inclined top slings. ASME BTH-1 governs either way.
Formula
Note: Educational sizing; certified lifting devices require qualified design, testing and marking.
Spreader Beam Calculator is a free spreader beam design for structural engineers, fabricators and site engineers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Spreader Beam Calculator
Bending in a lifting spreader and the section it needs. The calculation implements True spreader: pure compression. Lifting BEAM (central hook): M = P·L/4 (ASME BTH-1 — below-the-hook lifting devices). A 'spreader' with slings to a central hook is actually a lifting BEAM in bending — design it as one (this tool), or rig it as a true compression spreader with inclined top slings. ASME BTH-1 governs either way.
How to use Spreader Beam Calculator
- 1Enter Lifted load in kg.
- 2Enter Spreader length (pick points) in m.
- 3Enter Allowable stress (with impact factor) in MPa (Keep low: ASME BTH design factor 2–3 on yield).
- 4Read Max moment (central hook), Required S instantly — no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Spreader Beam Calculator?
- ✓Implements the standard formula — True spreader: pure compression. Lifting BEAM (central hook): M = P·L/4
- ✓Reference cited on-page: ASME BTH-1 — below-the-hook lifting devices
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Spreader Beam Calculator use?+
It computes True spreader: pure compression. Lifting BEAM (central hook): M = P·L/4, per ASME BTH-1 — below-the-hook lifting devices. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
A 'spreader' with slings to a central hook is actually a lifting BEAM in bending — design it as one (this tool), or rig it as a true compression spreader with inclined top slings. ASME BTH-1 governs either way. Note: Educational sizing; certified lifting devices require qualified design, testing and marking.
Can I use this for real structural design?+
It implements the exact textbook/code formula cited below the result and is ideal for sizing, checking and learning. Final designs should be verified by a qualified engineer against the full code with all load cases.
Is the Spreader Beam Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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