Surface Area Calculator

Find the surface area of a shape by entering the dimensions and selecting a unit of measurement.

Diagram of a rectangular prism showing l = length, w = width, and h = height

Surface Area:

 
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How to Find Surface Area

Surface area SA is the measure of the area of the surface of a 3-dimensional geometric shape or solid object. Surface area is measured in square units, such as square feet or square meters.

Surface area is equal to the area of each side of an object added together. For instance, the surface area of a cube is equal to the area of each of the six sides of the cube added up.

Graphic showing how to find the surface area of a cube

There are several types of surface area: curved surface area, lateral surface area, and total surface area.

Curved surface area is the area of the curved regions of an object.

Lateral surface area is the area the polygon faces of the object, not including the top and bottom bases.

Total surface area is the area of the whole object, including the curved surface, lateral faces, and the area of the base.

When calculating surface area, it is important to take all measurements using the same unit of measure. If your measurements are in different units, convert each measurement to the same unit first, then use the formulas below to solve.

The calculator above can easily find the surface area for a shape, but you can also find it using a formula.

Surface Area Formulas

There is a different surface area formula for each shape; see the formula for each one below.

Surface Area of a Cube

SA = 6a2

a = edge a length

Diagram of a cube showing e = edge length

Surface Area of a Rectangular Prism

SA = 2lw + 2lh + 2wh

l = length
w = width
h = height

Diagram of a rectangular prism showing l = length, w = width, and h = height

Surface Area of a Sphere

SA = 4πr2

r = radius

Diagram of a sphere showing r = radius

Surface Area of a Cylinder

SA = 2πr(r + h)

Base SA = 2πr2
Lateral SA = 2πrh

r = radius
h = height

Diagram of a cylinder showing r = radius and h = height

Surface Area of a Cone

SA = πr(r + r2 + h2)

Base SA = πr2
Lateral SA = πrr2 + h2

r = radius
h = height

Diagram of a cone showing r = radius and h = height

Surface Area of a Pyramid

SA = e2 + 2e(e ÷ 2)2 + h2

Base SA = e2
Lateral SA = 2e(e ÷ 2)2 + h2

e = edge length
h = height

Diagram of a pyramid showing e = edge length and h = height

Surface Area of a Triangular Prism

s = 1/2(a + b + c)

Base SA = s(s – a)(s – b)(s – c))
Lateral SA = h × (a + b + c)

Diagram of a triangular prism showing sides a, b, & c, and h = height

Surface Area of a Capsule

SA = 2πr(2r + h)

Curved SA = 4πr2
Lateral SA = 2πrh

r = radius
h = height

Diagram of a capsule showing r = radius and h = height

Surface Area of a Hemisphere

SA = 3πr2

Base SA = πr2
Curved SA = 2πr2

r = radius

Diagram of a hemisphere showing r = radius

Surface Area of a Spherical Cap

SA = π(r2 + h2) + πr2

Base SA = πr2
Curved SA = π(r2 + h2)

r = radius
h = height

Diagram of a cap showing r = radius and h = height

Formulas to find the surface area for several shapes

You’ll probably also find our volume calculator useful.