Crane Pick Radius Calculator

This calculator uses basic trigonometry for boom geometry. It treats the boom and jib as a straight line at the selected angle.

• Effective boom: L_eff = L_boom + L_jib
• Pick radius: R = Offset_pivot + (L_eff × cos(Angle)) + Offset_hook
• Boom tip height: H = Height_pivot + (L_eff × sin(Angle))
• Solving for boom length: L_eff = (R - offsets) / cos(Angle)
• Solving for boom angle: Angle = arccos((R - offsets) / L_eff)

1. Select a calculation mode based on what you know onsite.
2. Choose units and keep all inputs consistent.
3. Enter boom length, angle, and any jib or offsets.
4. For radius-based modes, enter your target radius.
5. Press Calculate to view results above the form.
6. Download CSV or PDF for records and lift planning notes.

1) Why pick radius drives capacity

Pick radius is the horizontal distance from the crane’s center of rotation to the load line. As radius increases, allowable capacity typically decreases sharply. For many mobile cranes, a small radius increase of 3–5% can reduce rated load by 5–15%, depending on chart range and configuration.

2) Inputs that change the geometry

Boom length, boom angle, jib length, and offsets combine into an effective reach. Even modest offsets matter: a 0.6 m (2 ft) centerline-to-pivot offset plus a 0.3 m (1 ft) hook block offset adds nearly 0.9 m (3 ft) to the working radius before any boom projection is counted.

3) Interpreting the output numbers

The calculator reports effective boom length, estimated pick radius, and boom tip height. Tip height supports clearance checks when placing loads over obstructions. Use the “clearance above load elevation” line as a quick indicator, then verify rigging length, load line angle, and required headroom onsite.

4) Practical field tolerance

Real lifts rarely match ideal geometry. Grade, outrigger settlement, boom deflection, and wind can change radius. A common planning practice is to add a small radius contingency (for example, +0.3 to +0.6 m / +1 to +2 ft) before checking the chart, especially for near-capacity picks.

5) Documentation and lift planning

Save results as CSV or PDF for lift planning files and toolbox talks. Record configuration (counterweight, outrigger state, parts of line), target radius, and elevation. Then confirm the correct chart page and duty rating for the same setup.

1) What is “pick radius” in simple terms?

It’s the horizontal distance from the crane’s rotation center to the load line at the hook. Load charts are typically indexed by this radius.

2) Does this calculator replace the crane load chart?

No. It estimates geometry only. Capacity must be verified on the manufacturer’s load chart for the exact configuration, reeving, outrigger setup, and wind limits.

3) Which angle definition is used here?

Boom angle is measured above the horizontal. A higher angle generally reduces radius and increases hook height for the same boom length.

4) Why add pivot and hook offsets?

Offsets represent real hardware geometry. Ignoring them can understate radius by 1–3 ft on some setups, which can change the charted capacity bracket.

5) What if my target radius seems unreachable?

Check offsets, jib entry, and angle limits. A long radius may require a longer boom or a lower angle, but both can reduce capacity.

6) How should I handle units?

Select meters or feet and keep every input in that unit. Mixing units is the most common cause of unrealistic radius or height outputs.

7) Is clearance above load elevation enough for safety?

It’s a quick indicator only. You still must account for rigging length, hook block, load line angle, swing path, and obstructions, then follow the lift plan.