Calculator Inputs
Results appear above this form after submission.
Use this page for planning support only. Confirm every lift with the exact manufacturer chart, site procedure, and competent lifting team.
Plotly Capacity Curve
The chart compares gross chart capacity, adjusted allowable capacity, and the entered suspended load at the selected operating radius.
Example Data Table
This sample illustrates how planning inputs change the remaining margin. Values below are examples for review and training.
| Scenario | Model | Boom (m) | Radius (m) | Suspended load (t) | Adjusted allowable (t) | Margin (t) |
|---|---|---|---|---|---|---|
| Steel beam placement | All Terrain 100 t | 48 | 15 | 13.40 | 16.71 | 3.31 |
| HVAC unit set | Mobile Telescopic 60 t | 30 | 12 | 8.90 | 13.79 | 4.89 |
| Precast panel pick | Rough Terrain 35 t | 24 | 18 | 5.60 | 5.82 | 0.22 |
| Pipe rack module | All Terrain 100 t | 60 | 21 | 10.10 | 9.55 | -0.55 |
Formula Used
1. Gross chart capacity is found by interpolation between boom lengths and operating radii in the selected reference chart.
2. Combined reduction factor = wind factor × setup factor × ground factor × dynamic factor × reserve factor × jib factor.
3. Adjusted allowable capacity = gross chart capacity × combined reduction factor.
4. Total suspended load = net load weight + rigging weight + hook block weight.
5. Net payload allowance = adjusted allowable capacity − rigging weight − hook block weight.
6. Margin = adjusted allowable capacity − total suspended load.
7. Utilization = total suspended load ÷ adjusted allowable capacity × 100.
8. Required line pull per part = total suspended load ÷ (parts of line × 0.90 efficiency).
These formulas are planning aids. Manufacturer notes for boom angle, counterweight, deductions, hoist reeving, and wind area still control the actual lift plan.
How to Use This Calculator
- Select the crane family that most closely matches your equipment.
- Enter boom length and operating radius from your planned lift position.
- Add the net load, rigging, and hook block weights to represent the true suspended load.
- Choose setup, ground, and dynamic conditions to reflect real site constraints.
- Enter wind speed, reserve percentage, jib length, and parts of line.
- Submit the form and review the result block that appears above the inputs.
- Study the graph and margin values before exporting the CSV or PDF report.
- Confirm the final lift with the exact crane manual, site engineering review, and approved method statement.
FAQs
1. What does this crane load chart calculator estimate?
It estimates gross chart capacity, adjusted allowable capacity, total suspended load, remaining margin, utilization, and line pull demand for a planned lift.
2. Why is the adjusted allowable capacity lower than the chart value?
The chart value is reduced by wind, outrigger setup, ground condition, lift dynamics, planning reserve, and jib use. Those factors create a more conservative planning number.
3. Should rigging and hook block weight be included?
Yes. The crane sees the full suspended weight, not only the payload. Add slings, spreader beams, shackles, lifting frames, and the hook block when applicable.
4. What is operating radius in crane planning?
Operating radius is the horizontal distance from the crane’s center of rotation to the load center. Capacity usually falls as this radius increases.
5. Why does wind speed affect the lift result?
Wind adds side loading and can increase boom, load, and tag line movement. Large sail areas or long booms can make wind limits more restrictive.
6. What does the line pull check tell me?
It estimates the average force carried by each rope part after applying a simple hoist efficiency. This helps flag reeving arrangements that are too light.
7. Can I use this for critical lifts?
Use it only for planning support. Critical lifts still require the exact manufacturer chart, engineered lift study, approved procedure, and competent supervision.
8. What should I do if the status shows over limit?
Reduce the suspended load, shorten the radius, improve setup conditions, increase reeving, or choose a larger crane before proceeding.