Crane Lift Planning Calculator

No -- treat it strictly as an educational estimate. Real crane capacity at radius comes from the manufacturer's certified load chart, an empirical table specific to that exact crane's configuration (counterweight, outrigger spread, boom configuration, and more), which cannot be reduced to a simple formula. Always verify any real lift against the crane's actual chart and your site's rigging safety plan before proceeding.

Real cranes lose rated capacity as the load moves farther from the crane's center because the load's weight creates a larger overturning (tipping) moment at a greater distance -- the same reason a wrench is easier to turn a bolt with when you push farther from the pivot. This calculator's simplified model approximates that falloff, but the exact capacity at any given radius must come from the manufacturer's certified chart, not this estimate.

It's this calculator's own conservative default, not a universal regulatory or manufacturer requirement -- it flags whether your Total Lifted Weight stays under 85% of the calculator's ESTIMATED Capacity at Radius. Real lift planning safety margins depend on the crane's certified chart, the specific rigging plan, load dynamics, wind conditions, and your site's own safety procedures, all of which vary by situation and are not captured by a single fixed percentage.

No -- this calculator caps Capacity at Radius at Crane SWL by design, since SWL is defined as the crane's maximum safe working load at its minimum radius, and no configuration at a larger radius can rate higher than that absolute ceiling. If the underlying derating formula would otherwise produce a number above SWL (which happens at small working radii), the result is simply held at SWL instead.

Yes -- Total Lifted Weight is Load Weight PLUS Rigging Weight, and Crane Utilization is based on that combined total, not Load Weight alone. Slings, shackles, spreader bars, and other rigging gear add real weight the crane has to lift, and ignoring it in a utilization calculation would understate how close to capacity the actual lift really is -- a mistake real riggers are trained never to make.