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Smaller Circles within a Large Circle - Calculator

Calculate the number of small circles that fits into an outer larger circle - ex. how many pipes or wires fits into a larger pipe or conduit.

The calculator below can be used to estimate the maximum number of small circles that fits into an outer larger circle. The calculator can be used to calculate applications like

  • the number of small pipes that fits into a large pipe or tube
  • the number of wires possible in a conduit
  • the number of fibers that fits in a connector
  • and similar applications


  • the inside diameter of an outer larger circle (or pipe, tube, conduit, connector), and
  • the outside diameters of small circles (or pipes, wires, fiber)

The default values are for a 10 inch pipe with 2 inch smaller pipes - dimensions according ANSI Schedule 40 Steel Pipes.

  • Note that the algorithm is quite simple - a circle or more may be added by rearranging the circles in a more sophisticated pattern.


(enable pop-up)

Number smaller circles within larger circle

Outside Diameter of a Bundle of Pipes

Tip! - the calculator above can be used to approximate the outside diameter of a bundle of pipes by inserting the small pipe diameter and do an iterative changing of the outside pipe diameter until the number of pipes calculated fits the number of pipes in the bundle.

Example - Outside diameter of a bundle with 30 pc. 1.5 inch pipes. The iterative process can be done like this

Outside diameter of a bundle with 30 pc. 1.5 inch pipes
Iteration No.eInputCalculated
Small Pipe DiameterLarge Pipe DiameterNo. of Pipes
1 1.5 10 32
2 1.5 9 26
3 1.5 9.8 31
4 1.5 9.6 29
5 1.5 9.7 31
6 1.5 9.65 30

Iteration 6 indicates that the outside diameter of the bundle of pipes is approximately 9.65 inches.

Calculate Maximum Number of Smaller Circles in Larger Circles

  • an array with multiple smaller and larger circles

In the boxes below

  • add a comma separated list with the sizes of the larger circles
  • add a comma separated list with the sizes of the smaller circles

An array with the maximum number of smaller circles within the larger circles will be created.

The default input values above are from ANSI Schedule 40 Steel Pipes .

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