Last updated on July 30th, 2025
A hollow cylinder is a 3-dimensional shape with two circular bases and a cylindrical surface, but it has an empty space inside. The surface area of a hollow cylinder includes the inner and outer curved surfaces and the areas of the two circular bases. In this article, we will learn about the surface area of a hollow cylinder.
The surface area of a hollow cylinder is the total area occupied by the outer and inner surfaces of the cylinder, along with the areas of the two circular bases. It is measured in square units.
A hollow cylinder is a 3D shape formed by two coaxial cylinders. It has a curved outer surface, a curved inner surface, and two circular bases, making up three distinct surface areas: the outer curved surface area, the inner curved surface area, and the total surface area including the bases.
A hollow cylinder has three types of surface areas: the outer curved surface area, the inner curved surface area, and the total surface area.
Look at the hollow cylinder below to see its surface area, height(h), outer radius(R), and inner radius(r).
A hollow cylinder has three types of surface areas:
Outer Curved Surface Area of a Hollow Cylinder
Inner Curved Surface Area of a Hollow Cylinder
Total Surface Area of a Hollow Cylinder
The outer curved surface area of a hollow cylinder is the area of the cylindrical surface on the outside.
The formula for the outer curved surface area (OCSA) is given as: Outer Curved Surface Area = 2πRh square units
Here, R is the outer radius of the hollow cylinder. h is the height of the hollow cylinder.
The inner curved surface area of a hollow cylinder is the area of the cylindrical surface on the inside.
The formula for the inner curved surface area (ICSA) is given as: Inner Curved Surface Area = 2πrh square units
Where r is the inner radius of the hollow cylinder. h is the height of the hollow cylinder.
The total surface area of a hollow cylinder includes the inner and outer curved surfaces, as well as the areas of the two circular bases.
The total surface area is calculated by using the formula: Total Surface Area = 2πRh + 2πrh + 2π(R^2 - r^2) square units
This includes the outer curved surface area, the inner curved surface area, and the areas of the two circular annuli (the difference between the areas of the large and small circles).
Students assume that the outer curved surface area (OCSA) and the inner curved surface area (ICSA) of a hollow cylinder are the same. This confusion arises because both involve the height and the radii. Always remember that OCSA uses the outer radius, while ICSA uses the inner radius.
Given R = 8 cm, h = 12 cm. Use the formula: OCSA = 2πRh = 2 × 3.14 × 8 × 12 = 603.2 cm²
Find the total surface area of a hollow cylinder with an outer radius of 10 cm, an inner radius of 7 cm, and a height of 15 cm.
TSA = 1615.4 cm²
Use the formula: TSA = 2πRh + 2πrh + 2π(R² - r²) = 2 × 3.14 × 10 × 15 + 2 × 3.14 × 7 × 15 + 2 × 3.14 × (10² - 7²) = 942 + 658.8 + 395.6 = 1996.4 cm²
A hollow cylinder has an outer radius of 6 cm, an inner radius of 4 cm, and a height of 10 cm. Find the inner curved surface area.
ICSA = 251.2 cm²
Use the formula: ICSA = 2πrh = 2 × 3.14 × 4 × 10 = 251.2 cm²
Find the total surface area of a hollow cylinder with an outer radius of 9 cm, an inner radius of 5 cm, and a height of 20 cm.
TSA = 2970.4 cm²
Use the formula: TSA = 2πRh + 2πrh + 2π(R² - r²) = 2 × 3.14 × 9 × 20 + 2 × 3.14 × 5 × 20 + 2 × 3.14 × (9² - 5²) = 1130.4 + 628 + 251.2 = 2009.6 cm²
The inner curved surface area of a hollow cylinder is 440 cm², with an inner radius of 7 cm. Find the height.
Height = 10 cm
Students often make mistakes while calculating the surface area of a hollow cylinder, which leads to wrong answers. Below are some common mistakes and the ways to avoid them.
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