# Trapezoidal Footing Formula with Example

## Trapezoidal Footing Concrete Formula

### As you know this type of footing makes from 2 different shapes.

### Trapezoidal Footing

- Rectangular Cubes (A)
- Truncated Pyramid Cubes (B)

### Please See the Image Below:

If you want to calculate whole shape volume, you have to calculate both shapes one by one.

**Let us Assume the whole shape size and dimensions.**

Column Size- 3m X 4m

Column to Top edge Spacing- 0.5m

Whole Footing Size -7m X 8m

The total height of footing is 6m

A Shape Height is 2m

B shape Height is 3m

**Now, we have the whole structure data, Now time to put all data in Formula.**

**First, we calculate Shape A**

as you can see shape A is a just rectangular shape

we know the whole size of the footing is 7m X8m and the A shape Height is 2 m.

Area of A shape

A1 = L x W

**A1= 8 x 7 = 56 m ^{2}**

**The volume of A Shape**

Volume = Area x height

**Volume = 56 x 2 = 112 m ^{3} ———-A**

### Now we are going to calculate the Truncated Pyramid Cubes’ shape

V = h/3 (A1+A2+√((A1 x A2) ) )

Where h is the height of the trapezoidal shape

A1 Area of the lower shape

A2 Area of upper shape

A1 = L x W A2 = L x W

A1 = 7 x 8 A2 = 5 x 4

A1 = 56 m^{2 } A2 = 20 m^{2}

**V =3/3 (56+20+√((56 x 20) ) )**

V =109.46 m^{3}** ————B**

Above we calculate the volume of A (112 m^{3})

Now we add A+B= 221.46 m^{3}

Trapezoidal Footing Total Volume is 221.46 m^{3}.

For a Better Experience, you can watch this video.