Calculate boom length, load, or radius from two inputs using only a simplified boom model with short tons, meters, feet, and yards.

Boom Length (Simplified) Calculator

Enter any 2 values to calculate the missing variable (simplified model, not a load chart)

Boom Length Formula

The simplified boom length model uses a fixed reference load of 10 short tons. The calculator converts length inputs to meters and load inputs to short tons before applying the formula, then converts the result back to the unit you selected.

BL = R * (1 + L / Láµ£ef)
R = BL / (1 + L / Láµ£ef)
L = (BL / R - 1) * Láµ£ef
  • BL = boom length
  • R = working radius
  • L = load
  • L_ref = reference load, equal to 10 short tons in this simplified model

The boom length function calculates the required boom length when you enter load and radius. The radius function rearranges the same relationship to find the working radius from a known load and boom length. The load function estimates the load implied by a given boom length and radius. This is a simplified relationship and is not a substitute for a crane load chart, lift plan, manufacturer data, or site-specific engineering review.

Common Unit Conversions Used

The calculator uses the following conversions before applying the formulas.

Input type Unit Base conversion
Load Short tons 1 short ton = 1 short ton
Load Metric tons 1 metric ton = 1.10231 short tons
Length Meters 1 meter = 1 meter
Length Feet 1 foot = 0.3048 meters
Length Yards 1 yard = 0.9144 meters

Simplified Result Checks

Load Radius Calculated boom length
0 short tons 10 meters 10 meters
5 short tons 10 meters 15 meters
10 short tons 10 meters 20 meters
20 short tons 10 meters 30 meters

Example

Example 1: Calculate boom length

You enter a load of 10 short tons and a radius of 12 meters.

BL = 12 * (1 + 10 / 10)
BL = 12 * 2 = 24 meters

The simplified boom length is 24 meters.

Example 2: Calculate load

You enter a boom length of 30 meters and a radius of 15 meters.

L = (30 / 15 - 1) * 10
L = (2 - 1) * 10 = 10 short tons

The simplified load is 10 short tons.

FAQ

Is this the same as a crane load chart?

No. This is a simplified calculation based only on load, radius, and a fixed reference load. A real crane load chart accounts for crane model, boom configuration, counterweight, outrigger setup, boom angle, jib, wind, ground conditions, rigging weight, and other limits.

Why must boom length be at least as long as the radius when calculating load?

In this simplified model, the load formula is L = (BL / R - 1) * L_ref. If boom length is shorter than radius, BL / R is less than 1, which produces a negative load. The calculator blocks that because negative load is not meaningful here.

Can I use feet, yards, meters, short tons, and metric tons together?

Yes. You can mix the available units. The calculator converts lengths to meters and loads to short tons internally, performs the calculation, then returns the missing value in the unit selected for that field.