Calculate ideal horizontal reach from rope or chain length and angle, add a user-supplied radial buffer, or compare circular geometry. These calculations do not establish safe playground use zones, fence placement, crane working radii or lifting capacity.

Ideal point geometry only, with angles 0°–90° from vertical. A buffer or geometric fit does not establish a safe playground use zone, crane radius or lifting capacity.

Optional settings

Blank means zero. This is a user-supplied allowance, not a safety standard.

Related Calculators

Swing Radius Formula

The following formula is used to calculate the swing radius.

R = L × sin(θ)

Variables:

  • R is the swing radius (meters)
  • L is the length of the rope or chain (meters)
  • θ is the angle from vertical (degrees)

Multiply rope or chain length by sin(θ), with θ measured 0°–90° from vertical. Select radius, length or angle explicitly. Circle-area and circumference inverses find the unbuffered radius before adding the optional buffer; blank buffer means zero.

What is a Swing Radius?

Here swing radius is the horizontal displacement of an ideal point at the end of a straight rope or chain from the vertical line through its pivot. The buffered circle is only a layout model. Actual playground use zones require swing-specific guidance, including pivot height and protective surfacing; crane operation requires manufacturer data. A geometric fit is not a safety approval.

How to Calculate Swing Radius?

The following steps outline how to calculate the Swing Radius.

  1. First, determine the length of the rope or chain (L) in meters.
  2. Next, determine the angle from vertical (θ) in degrees.
  3. Convert the angle from degrees to radians by multiplying it by π/180.
  4. Use the formula R = L * sin(θ) to calculate the Swing Radius (R) in meters.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Length of Rope/Chain (L) = 5 meters

Angle from Vertical (θ) = 30 degrees. R = 5 × sin(30°) = 2.5 meters, before any buffer.