Rectangular Prism Calculator

Table of contents:
Let’s say you want to know how much water your new aquarium or swimming pool can hold – how do you go about it? Use a rectangular prism calculator and find out! Such a tool can help you with cuboid volumes, rectangular prism diagonal values, and surface areas as well. Read on to find out more.

What is a Rectangular Prism?

A rectangular prism is a solid shape with six rectangle faces and three dimensions. Some people also call them an oblique, a cuboid, or a rectangular hexahedron. A right rectangular prism is also an acceptable term. The shape can have sides that lean to one side as well.

Rectangular Prism Calculator: How to Find the Volume of a Right Rectangular Prism?

To work out the volume of a rectangular prism, you need to use the formula below. 
In the formula, you will see three letters = h, w, and l. 

H = height
W = width 
L = length

The formula is h x w x l

Let’s say you want to find the volume of an apple carton. Follow these steps with example measurements below.

   1.	Identify the length of the box - 20 inches long

   2.	Identify its width – 18 inches wide 

   3.	Measure its height – 13 inches high

   4.	Calculate the cuboid volume 

Volume = 13 x 18 x 20 = 4,680 in³

Rectangular Prism Calculator: How to Find the Area of a Right Rectangular Prism?

Identifying the area of a rectangular prism involves a long-winded sum, but it’s as effortless as determining the volume – especially with a rectangular prism calculator. As you know, the prism has six faces which include three parallel rectangle pairs. Add all the faces together to get the surface area. 

The formula is as follows: 

Surface area = 2 x (h x w) + 2 x (h x l) + 2 x (l x w) = 2 x (h x w + h x l + I x w)

Using the same dimensions of the apple carton above, we’ll work through it step by step.

   1.	Calculate the surface areas
Height x width = 13 x 18 = 234 in²
Height x length = 13 x 20 = 260 in²
Length x width = 20 x 18 = 360 in²

   2.	Add all figures together then divide by two
260 + 360 + 234 / 2 = 427 in²

The apple carton’s surface area is 427 in².
Alternatively, you can use a rectangular prism calculator instead of having to work the value out by hand.

Rectangular Prism Calculator: How to Find the Diagonal of a Right Rectangular Prism?

If you want to know the diagonal value of a rectangular prism, then you will see it’s a fairly straightforward process.

Use this formula:

Diagonal = √ (l² + h² + b²)

The formula is very similar to that in use with the Pythagorean theorem.

Calculating Volumes of Shapes

Did you know the rectangular prism is not the only shape for which you can use a calculator to get the volume? There are several others. If you ever need to find the volume of a cone, pyramid, sphere, or any other three-dimensional shape, there is sure to be a calculator to help.

Rectangular Prism Calculator

Sphere Calc: find V, A, d
Cone Volume Calculator
Cylinder Volume Calculator
... more