The cross-sectional area calculator determines the area for different types of beams. A beam is a very crucial element in construction. The load bearing member of bridges, roofs and floors in buildings are available in different cross-sections. Read on to understand how to calculate cross-sectional area of *I* section, *T* section, *C* beam, *L* beam, round bar, tube, and beams with rectangular and triangular cross-sections.

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## What is a cross-section and how to calculate a cross-sectional area?

A cross-section is defined as the common region obtained from the intersection of a plane with a 3D object. For instance, consider a long circular tube cut (intersect) with a plane. You'll see a couple of concentric circles. The concentric circles are the cross-section of a tube. Similarly, the beams — *L*, *I*, *C*, and *T* — are named based on the cross-section shape.

We also know that the inner diameter d is related to thickness t and outer diameter D as:

d = D - 2 * tTherefore, the area of cross-section becomes:

AC = π * (D2 - (D - 2 * t)2) / 4Similarly, the area of cross-section for all other shapes having width W, height H, and thicknesses t1 and t2 are given in the table below.

Cross-sections SectionAreaHollow Rectangle | (H * W) - ((W - 2t1) * (W - 2t2)) |

Rectangle | W * H |

I | 2 * W * t1 + (H - 2 * t1) * t2 |

C | 2 * W * t1 + (H - 2 * t1) * t2 |

T | W * t1 + (H - t1) * t2 |

L | W * t + (H - t) * t |

Isosceles Triangle | 0.5 * B * H |

Equilateral Triangle | 0.4330 * L2 |

Circle | 0.25 * π * D2 |

Tube | 0.25 * π *(D2 - (D - 2 * t)2) |

## How to find cross-sectional area?

Follow the steps below to find the cross-sectional area.Step 1: Select the**shape**of cross-section from the list, say,

*Hollow rectangle*. An illustration of the cross-section and the related fields will now be visible.Step 2: Enter the

**width**of the hollow rectangle, W.Step 3: Fill in the

**height**of the cross-section, H.Step 4: Insert the

**thickness**of the hollow rectangle, t.Step 5: The calculator will return the

**area of the cross-section**.

## Example: Using the cross-sectional area calculator.

Find the cross-sectional area of tube having outer diameter of 10 mm and a thickness of 1 mm.

Step 1: Select the**shape**of cross-section from the list, i.e.,

*Tube*.Step 2: Enter the

**outer diameter**of tube, D = 10 mm.Step 3: Insert the

**thickness**of the tube, t = 1 mm.Step 4: The area of cross-section is :AC = π * (D2 - (D - 2 * t)2) / 4AC = π * (102 - (10 - 2 * 1)2) / 4 = 28.274 mm2

## Applications of cross-section shapes

*Did you know?*

*I*or

*H*beam is used extensively in railway tracks.

*T*beams are found in use in early bridges and is used to reinforce structures to withstand large loads on floors of bridges and piers.

## FAQ

### How to calculate cross-sectional area of a pipe?

To calculate cross-section of a pipe:

**Subtract**the squares of inner diameter from the outer diameter.

**Multiply**the number with π.

**Divide**the product by 4.

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### How to calculate area of an I section?

The area of I section with total width W, height H and having thickness t can be calculated as:

Area = 2 × W × t + (H - 2 × t) × t### How to calculate area of an T section?

The area of a T section with total width W, height H and having thickness t can be calculated as:

Area = W × t + (H - 2 × t) × t### What is the cross section of a cube?

The cross-section of a cube is a **square**. Similarly, for a cuboid, it is either a square or a rectangle.