**Formula**:

The formula is:

**$\text{SA} = 2lw + 2lh + 2wh$**
**Variables:**

**Variable** |
**Meaning** |

SA |
Surface Area of the cuboid (total area of all six faces) |

l |
Length of the cuboid |

w |
Width of the cuboid |

h |
Height of the cuboid |

### How to Calculate?

First of all, you have to measure the length (l), width (w), and height (h) of the cuboid. Now, calculate the area of each pair of opposite faces by multiplying the dimensions: length × width, length × height, and width × height. Next to that, multiply each of these areas by 2 (since each face has an opposite face of the same size). Finally, sum these three results to find the total surface area (SA) of the cuboid.

### Solved Calculations:

**Example 1:**

**Given**:

- Length (l) = 5 cm
- Width (w) = 3 cm
- Height (h) = 4 cm

**Calculation** |
**Instructions** |

**Step 1:** SA = $2lw + 2lh + 2wh$ |
Start with the formula. |

**Step 2:** SA = $2(5 \times 3) + 2(5 \times 4) + 2(3 \times 4)$ |
Replace l, w, and h with 5 cm, 3 cm, and 4 cm, respectively. |

**Step 3:** SA = $2(15) + 2(20) + 2(12)$ |
Multiply the dimensions: $5 \times 3 = 15$, $5 \times 4 = 20$, $3 \times 4 = 12$. |

**Step 4:** SA = $30 + 40 + 24$ |
Multiply each result by 2. |

**Step 5:** SA = 94 cm² |
Add the three products to get the total surface area. |

**Answer**:

The surface area of the cuboid is **94 cm²**.

**Example 2:**

**Given**:

- Length (l) = 8 cm
- Width (w) = 6 cm
- Height (h) = 5 cm

**Calculation** |
**Instructions** |

**Step 1:** SA = $2lw + 2lh + 2wh$ |
Start with the formula. |

**Step 2:** SA = $2(8 \times 6) + 2(8 \times 5) + 2(6 \times 5)$ |
Replace l, w, and h with 8 cm, 6 cm, and 5 cm, respectively. |

**Step 3:** SA = $2(48) + 2(40) + 2(30)$ |
Multiply the dimensions: $8 \times 6 = 48$, $8 \times 5 = 40$ $6 \times 5 = 30$. |

**Step 4:** SA = $96 + 80 + 60$ |
Multiply each result by 2. |

**Step 5:** SA = 236 cm² |
Add the three products to get the total surface area. |

**Answer**:

The surface area of the cuboid is **236 cm²**.

**What is Surface Area of a Cuboid Calculation?**

When you have the right calculator then calculating the surface area of a cuboid is simple. A cuboid, also known as a rectangular box, has six faces, and its surface area is the total area of all these faces combined.

Using a surface area calculator for a cuboid makes it easy, especially when you need the answer in specific units like square meters or square feet. It allows you to input the dimensions and instantly get the total surface area. For more complex calculation like finding surface lateral area (excluding top and bottom face ) or for the surface area of an open cuboid, special calculators are available online that can even provide results for standard cuboids or semi open shape surface area.

**Final Words:**

The Surface Area of Cuboid Calculator makes it easy to know how much surface a cuboid has. Its application is important in various fields including construction, packaging and design. It is a time saving and indispensable tool that you must use.