Mobile Cranes
How to Size a Mobile Crane for Your Lift
Crane sizing is not just about load weight: a crane's nominal capacity does not mean it can lift that load at every radius. You need the load weight, lift radius, lift height and site/ground conditions to select the right crane from the manufacturer's load chart.
| Required inputs | Load weight, lift radius, lift height, site access |
|---|---|
| Key caveat | Nominal capacity ≠ capacity at every radius |
| Where final capacity comes from | The manufacturer's load chart for that configuration |
Why radius changes everything
A crane's capacity drops sharply as the lift radius (horizontal distance from the crane's centre of rotation to the load) increases. A crane rated at 100 tons at a short radius might only lift a fraction of that at a longer radius.
This is why a 'ton' figure alone is not enough to select a crane: the combination of weight, radius and height determines which machine and configuration is actually required.
What to send for an accurate recommendation
Share the load weight, the lift radius, the required lift height, and any site access constraints (ground bearing capacity, overhead obstructions, working hours). This lets the right crane and configuration be selected against the manufacturer's load chart rather than guessed from tonnage alone.
Common mistakes
- Selecting a crane by nominal tonnage without checking the load chart at the actual working radius.
- Not accounting for rigging weight and outrigger/ground-bearing requirements.
Reviewed 2026-09-01. Technical references: manufacturer documentation and internal fleet data.