🕑 Reading time: 1 minute

The trapezoidal footing formula is used to determine the volume of a trapezoidal footing from the respective drawing specifications. Here, the trapezoidal footing formula is explained and clarified with the help of an example.## Trapezoidal Footing Formula

As shown in figure-1 below, the trapezoidal footing is a combination two components:- Truncated Pyramid
- Rectangular Cuboid

**The volume of trapezoidal footing = Sum of (Volume of truncated pyramid + Volume of Rectangular Cuboid)**

**Example - Calculation Using Trapezoidal Footing Formula**

The trapezoidal footing formula can be explained with an example. Consider a trapezoidal footing arrangement as shown in figure-3 below.
Here, a square trapezoidal footing is taken into consideration. Let a= 0.8 m and b = 0.8m.
From, the figure-2, A = 1.5m and B = 1.5m
Hence,
- A1= A x B = 1.5 x 1.5 = 2.25m
^{2} - A2 = a x b = 0.8 x 0.8m = .64m
^{2} - ht = 0.3m

^{3}From Eq.3 and substituting the respective values Vc = 1.5 x 1.5 x 0.2 = 0.45m

^{3}From Eq.1,

**Volume of Trapezoidal Footing V = Vt + Vc = 0.614 + 0.45 = 1.064m**The formula can be used for trapezoidal footing which is either rectangle or square in dimension.

^{3}