Lift Planning — CG from Two Scale Readings
CG from Two Scale Readings for engineered lift planning.
Two scales (or two load cells, or two forklifts with gauges) turn an unknown machine into a documented lift: total weight AND CG in one measurement. Do it once at the shop, stencil the result on the frame, and every future rigger inherits the answer instead of the guess.
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.
CG from Two Scale Readings for engineered lift planning. A free crane load, wind & rigging safety tool — no sign-up, no upload, instant results in your browser.
About Lift Planning — CG from Two Scale Readings
Lift Planning — CG from Two Scale Readings computes the governing relationship x_CG = R_B·L / (R_A + R_B) live as you type. Two scales (or two load cells, or two forklifts with gauges) turn an unknown machine into a documented lift: total weight AND CG in one measurement. Do it once at the shop, stencil the result on the frame, and every future rigger inherits the answer instead of the guess. 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 Lift Planning — CG from Two Scale Readings
- 1Enter your values — Scale A reading, Scale B reading, Support spacing (sensible defaults are pre-filled).
- 2Read the live results: Total weight, CG from support A.
- 3Check the "with your numbers" line to see x_CG = R_B·L / (R_A + R_B) substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Lift Planning — CG from Two Scale Readings?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula x_CG = R_B·L / (R_A + R_B) with authoritative sources cited on the page (ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; OSHA 29 CFR 1926 Subpart CC — Cranes & derricks in construction; DNV-ST-N001 — Marine operations (DAF methodology))
- ✓Two scales (or two load cells, or two forklifts with gauges) turn an unknown machine into a documented lift: total weight AND CG in one measurement.
- ✓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 lift planning — cg from two scale readings use?+
It evaluates x_CG = R_B·L / (R_A + R_B), exactly as published. Sources: ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; OSHA 29 CFR 1926 Subpart CC — Cranes & derricks in construction; DNV-ST-N001 — Marine operations (DAF methodology). 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?+
Two scales (or two load cells, or two forklifts with gauges) turn an unknown machine into a documented lift: total weight AND CG in one measurement. 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?+
CG from Two Scale Readings for engineered lift planning. A free crane load, wind & rigging safety tool. Do it once at the shop, stencil the result on the frame, and every future rigger inherits the answer instead of the guess. 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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