1. Choose a Shape
Select a cube, rectangular prism, sphere, cylinder, cone or triangular prism from the shape menu.
Geometry Calculator
Surface Area Calculator
Calculate the total surface area of cubes, spheres, cylinders, cones, rectangular prisms and triangular prisms. Get accurate square-unit results with formulas and complete calculation steps.
Select a Three-Dimensional Shape
Choose a shape and enter its required measurements.
Selected formula
SA = 6a²
Surface Area Result
Your total area and calculation breakdown appear here.
Total Surface Area
0
cm²
Select a shape, enter its dimensions and calculate.
Selected Shape
Cube
Side or Curved Area
—
Base Area
—
Square Metres
—
Formula applied
SA = 6a²
Calculation Steps
- Select the three-dimensional shape.
- Enter all required measurements.
- Select Calculate Surface Area.
How to Use the Surface Area Calculator
Find the exposed exterior area of a three-dimensional shape in three straightforward steps.
2. Enter Dimensions
Enter the required length, width, height, radius or side measurements using the same unit.
3. Review the Area
View the total surface area, component areas, formula, square-metre conversion and calculation steps.
What Is Surface Area?
Surface area is the total area covered by all exterior faces and curved surfaces of a three-dimensional object. It tells you how much material would be needed to completely cover the outside of the object.
Surface area is always expressed in square units, such as square centimetres, square metres, square inches or square feet. This differs from volume, which is measured in cubic units and represents the space inside an object.
Total and Lateral Surface Area
Total surface area includes every exposed face or surface. Lateral surface area includes only the side or curved surfaces and usually excludes the bases.
Why Surface Area Is Useful
Surface area calculations are commonly used for painting, packaging, construction, manufacturing, insulation, wrapping and material estimation.
Cube Surface Area Example
Suppose a cube has a side length of 5 centimetres.
Surface area = 6 × side²
Surface area = 6 × 5²
Surface area = 6 × 25
Total surface area = 150 cm²
Surface Area Formula Table
Use the appropriate formula based on the shape and available measurements.
| Shape | Required Measurements | Total Surface Area Formula |
|---|---|---|
| Cube | Side length: a | SA = 6a² |
| Rectangular Prism | Length: l, width: w, height: h | SA = 2(lw + lh + wh) |
| Sphere | Radius: r | SA = 4πr² |
| Cylinder | Radius: r, height: h | SA = 2πr² + 2πrh |
| Cone | Radius: r, height: h | SA = πr² + πr√(r² + h²) |
| Triangular Prism | Triangle sides: a, b, c, prism length: L | SA = 2B + (a + b + c)L |
Frequently Asked Questions
Helpful answers about surface area, square units and three-dimensional shapes.
Area measures a two-dimensional region, while surface area measures the combined area of all exterior surfaces of a three-dimensional object.
Surface area is measured in square units, including mm², cm², m², in², ft² and yd².
Square the side length and multiply the result by six. The formula is SA = 6a².
Yes. Total cylinder surface area includes the top base, bottom base and curved side. Its formula is 2πr² + 2πrh.
Yes. When radius and vertical height are known, the slant height is calculated as √(r² + h²). The slant height is then used in the surface area formula.
Lateral surface area measures the side or curved surfaces of a solid while excluding its base or bases.
Yes. Convert every measurement to the same unit before calculating surface area to avoid an incorrect result.