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Surface Area Calculator

Find the surface area of a cube, box, sphere, hemisphere, cylinder, cone, frustum, capsule, spherical cap, ellipsoid, pyramid or triangular prism, with the lateral and base areas.

Change the values and press Calculate to work out your own figures.

Cube

Enter the edge.

The length of an edge.
The unit of every measurement; the answer is then also given in other units.
Result
Surface area of the cube
54 ft²
Area of one face
9 ft²

The surface area of the cube is 54 ft².

In other units
AmountUnit
5.01676416m²
50,167.6416cm²
54ft²
7,776in²
6yd²
0.001239669422acres
Show the working
  1. S = 6a²
  2. Surface area = 54 ft²

Rectangular box (cuboid)

Enter the length, width and height.

The longer side.
The shorter side.
The perpendicular height.
The unit of every measurement; the answer is then also given in other units.
Result
Surface area of the rectangular box
52 ft²

The surface area of the rectangular box is 52 ft².

In other units
AmountUnit
4.83095808m²
48,309.5808cm²
52ft²
7,488in²
5.777777778yd²
0.001193755739acres
Show the working
  1. S = 2(lw + lh + wh)
  2. Surface area = 52 ft²

Sphere (ball)

Enter the radius.

From the centre to the edge.
The unit of every measurement; the answer is then also given in other units.
Result
Surface area of the sphere
113.0973355 ft²
Exact
36π ft²

The surface area of the sphere is 113.0973355 ft² (36π ft²).

In other units
AmountUnit
10.50708629m²
105,070.8629cm²
113.0973355ft²
16,286.01632in²
12.56637061yd²
0.002596357565acres
Show the working
  1. S = 4 π r²
  2. Surface area = 113.0973355 ft²

Hemisphere

Enter the radius.

From the centre to the edge.
The unit of every measurement; the answer is then also given in other units.
Result
Total surface area of the hemisphere
84.82300165 ft²
Exact
27π ft²
Curved surface
56.54866776 ft² (18π)
Base
28.27433388 ft² (9π)

The total surface area of the hemisphere is 84.82300165 ft² (27π ft²).

In other units
AmountUnit
7.880314715m²
78,803.14715cm²
84.82300165ft²
12,214.51224in²
9.424777961yd²
0.001947268174acres
Show the working
  1. S = 2πr² (curved) + πr² (base) = 3πr²
  2. Total surface area = 84.82300165 ft²

Cylinder

Enter the radius and height.

From the centre to the edge.
The perpendicular height.
The unit of every measurement; the answer is then also given in other units.
Result
Total surface area of the cylinder
131.9468915 ft²
Exact
42π ft²
Lateral surface
75.39822369 ft² (24π)
Each end
28.27433388 ft² (9π)

The total surface area of the cylinder is 131.9468915 ft² (42π ft²).

In other units
AmountUnit
12.25826733m²
122,582.6733cm²
131.9468915ft²
19,000.35237in²
14.66076572yd²
0.003029083826acres
Show the working
  1. S = 2πrh + 2πr²
  2. Total surface area = 131.9468915 ft²

Cone

Enter the radius and height.

From the centre to the edge.
The perpendicular height.
The unit of every measurement; the answer is then also given in other units.
Result
Total surface area of the cone
75.39822369 ft²
Lateral surface
47.1238898 ft²
Base
28.27433388 ft² (9π)
Slant height
5 ft

The total surface area of the cone is 75.39822369 ft².

In other units
AmountUnit
7.004724191m²
70,047.24191cm²
75.39822369ft²
10,857.34421in²
8.37758041yd²
0.001730905043acres
Show the working
  1. S = πr² + πr√(r² + h²)
  2. Total surface area = 75.39822369 ft²

Conical frustum

Enter the bottom radius, top radius and height.

The larger radius.
The smaller radius (top and bottom for a barrel).
The perpendicular height.
The unit of every measurement; the answer is then also given in other units.
Result
Total surface area of the conical frustum
164.3398183 ft²
Lateral surface
101.5079652 ft²
Top
12.56637061 ft²
Bottom
50.26548246 ft²

The total surface area of the conical frustum is 164.3398183 ft².

In other units
AmountUnit
15.26766871m²
152,676.6871cm²
164.3398183ft²
23,664.93383in²
18.25997981yd²
0.003772723101acres
Show the working
  1. S = π(R + r)√((R − r)² + h²) + πr² + πR²
  2. Total surface area = 164.3398183 ft²

Capsule

Enter the radius and height.

From the centre to the edge.
The perpendicular height.
The unit of every measurement; the answer is then also given in other units.
Result
Surface area of the capsule
207.3451151 ft²
Exact
66π ft²

The surface area of the capsule is 207.3451151 ft² (66π ft²).

In other units
AmountUnit
19.26299153m²
192,629.9153cm²
207.3451151ft²
29,857.69658in²
23.03834613yd²
0.00475998887acres
Show the working
  1. S = 2πr(2r + h)
  2. Surface area = 207.3451151 ft²

Spherical cap

Enter the radius and height.

From the centre to the edge.
The perpendicular height.
The unit of every measurement; the answer is then also given in other units.
Result
Total surface area of the spherical cap
113.0973355 ft²
Exact
36π ft²
Curved surface
62.83185307 ft² (20π)
Base
50.26548246 ft² (16π)

The total surface area of the spherical cap is 113.0973355 ft² (36π ft²).

In other units
AmountUnit
10.50708629m²
105,070.8629cm²
113.0973355ft²
16,286.01632in²
12.56637061yd²
0.002596357565acres
Show the working
  1. Curved: 2πRh; base: π a² with a² = h(2R − h)
  2. Total surface area = 113.0973355 ft²

Ellipsoid

Enter the semi-axis a, semi-axis b and semi-axis c.

First semi-axis.
Second semi-axis.
Third semi-axis.
The unit of every measurement; the answer is then also given in other units.
Result
Surface area (approximate) of the ellipsoid
48.97193333 ft²

The surface area (approximate) of the ellipsoid is 48.97193333 ft².

In other units
AmountUnit
4.549641481m²
45,496.41481cm²
48.97193333ft²
7,051.9584in²
5.441325926yd²
0.001124240894acres
Show the working
  1. S ≈ 4π((aᵖbᵖ + aᵖcᵖ + bᵖcᵖ) ÷ 3)^(1/p), p = 1.6075 (Thomsen's formula, within about 1.1%)
  2. Surface area (approximate) = 48.97193333 ft²

Square pyramid

Enter the edge and height.

The length of an edge.
The perpendicular height.
The unit of every measurement; the answer is then also given in other units.
Result
Total surface area of the square pyramid
96 ft²
Lateral surface
60 ft²
Base
36 ft²
Slant height
5 ft

The total surface area of the square pyramid is 96 ft².

In other units
AmountUnit
8.91869184m²
89,186.9184cm²
96ft²
13,824in²
10.66666667yd²
0.00220385675acres
Show the working
  1. S = a² + 2a√(a²/4 + h²)
  2. Total surface area = 96 ft²

Triangular prism

Enter the side a, side b, side c and length.

First side.
Second side.
Third side.
The longer side.
The unit of every measurement; the answer is then also given in other units.
Result
Total surface area of the triangular prism
132 ft²
Each end
6 ft²
Sides
120 ft²

The total surface area of the triangular prism is 132 ft².

In other units
AmountUnit
12.26320128m²
122,632.0128cm²
132ft²
19,008in²
14.66666667yd²
0.003030303031acres
Show the working
  1. S = 2 × base area + (a + b + c) × length
  2. Total surface area = 132 ft²

How to use it

Enter the edge. Enter the length, width and height. Enter the radius. Enter the radius. Enter the radius and height. Enter the radius and height. Enter the bottom radius, top radius and height. Enter the radius and height. Enter the radius and height. Enter the semi-axis a, semi-axis b and semi-axis c. Enter the edge and height. Enter the side a, side b, side c and length.

Enter the measurements (decimals, fractions such as 3/4, or mixed numbers such as 1 1/2) and, if you like, their unit; the answer is then also given in other units. Show the working gives the formula.

Key facts

Sphere S = 4πr²; cylinder S = 2πr² + 2πrh; cone S = πr² + πr√(r² + h²)

Lateral and total area

The lateral area is the curved or side surface only; the total adds the ends. Painting a closed can needs the total; a label needs only the lateral area.

Questions

What is the surface area of a sphere of radius 3?

36π ≈ 113.0973355.

Is a cylinder's area including the ends?

The total includes both ends; the lateral area is shown separately.

Reviewed by RK Calculator Team. Updated 2026-09-26.

Formulas

Sphere S = 4πr²; cylinder S = 2πr² + 2πrh; cone S = πr² + πr√(r² + h²)

Sources

Limitations

  • All measurements in one calculation use the same unit; the answer is also given in other units.
  • Measurements up to 10¹⁵.

Formula version 0.1.0Reviewed