Frustum Calculator
Calculate Area & Volume for Truncated Cones & Pyramids.
Work Shown
In geometry, a frustum is a three-dimensional shape formed when the top of a cone or pyramid is cut off parallel to its base. This creates a solid with two flat, parallel surfaces of different sizes and slanted side faces connecting them. You can see frustum shapes in everyday objects such as buckets, lampshades, flower pots, containers, and tapered building structures.
Because a frustum has both top and bottom bases plus sloping sides, calculating its surface area and volume can be confusing when done manually. A Frustum Surface Area Calculator makes this process simple by using accurate formulas and showing instant results.
This guide explains how the calculator works, the formulas it uses, and how you can apply it in real-life projects and studies.
What the Frustum Surface Area Calculator Is
A Frustum Surface Area Calculator is an online geometry tool that finds:
-
Lateral (side) surface area
-
Total surface area
-
Volume
It works for different frustum types, including:
-
Conical frustum (truncated cone)
-
Square pyramid frustum
-
Rectangular pyramid frustum
You only need to enter the correct dimensions, and the calculator gives fast and accurate results.
How the Frustum Surface Area Calculator Works
Inputs You Enter
Depending on the shape, the calculator may ask for:
-
Larger base radius or side length
-
Smaller top radius or side length
-
Vertical height
All values should be entered in the same unit system, such as meters, centimeters, or feet.
Calculation Process
The calculator follows these steps:
-
Finds the slant height
-
Calculates the lateral surface area
-
Adds the top and bottom areas
-
Computes the volume
Output You Get
You receive:
-
Lateral surface area
-
Total surface area
-
Volume
Results are displayed in square and cubic units.
Key Formulas Used
Slant Height of a Conical Frustum
l = \sqrt{(R - r)^2 + h^2}Where:
-
R = larger base radius
-
r = smaller top radius
-
h = vertical height
Lateral Surface Area
LSA = \pi (R + r) \times lThis gives the curved side area only.
Total Surface Area
TSA = \pi (R + r) l + \pi (R^2 + r^2)This includes both the curved surface and the two circular bases.
Volume of a Conical Frustum
V = \frac{\pi h}{3} (R^2 + Rr + r^2)This shows how much space the frustum can hold.
Step-by-Step Examples
Example 1: Surface Area
R = 10 cm
r = 4 cm
h = 24 cm
First, find slant height:
l = \sqrt{(10 - 4)^2 + 24^2} = 25Now find lateral surface area:
LSA = \pi(10 + 4) \times 25 = 350\piNow add base areas:
TSA = 350\pi + \pi(100 + 16) = 466\piSo, total surface area = 466π cm².
Example 2: Volume
Using the same values:
V = \frac{\pi(24)}{3}(100 + 40 + 16) V = 1248\pi \text{ cm}^3Features of the Frustum Surface Area Calculator
Multiple Shape Support
Works for cone and pyramid frustums.
Step Display
Shows calculations clearly.
Fast Results
Instant answers.
Unit Flexibility
Accepts metric and imperial units.
Accurate Geometry
Uses standard formulas.
Uses and Applications
Manufacturing
Helps design tapered containers and parts.
Construction
Used for architectural structures.
Packaging
Calculates label and material area.
Education
Makes geometry learning easier.
DIY Projects
Useful for home designs.
Helpful Tips for Best Results
Keep Units Consistent
Use the same unit for all values.
Measure Accurately
Small errors change results.
Check Shape Type
Use cone formulas only for cone frustums.
Use Slant Height
Surface area needs slanted length.
Round at the End
Avoid early rounding.
Common Mistakes to Avoid
Mixing Units
Never mix cm with inches.
Skipping Slant Height
It is required for area.
Using Wrong Formula
Different shapes use different equations.
Forgetting Base Areas
Total area includes top and bottom.
Guessing Dimensions
Always measure properly.
Frequently Asked Questions
What Is a Frustum?
A shape made by cutting the top of a cone or pyramid.
What Is Lateral Surface Area?
Only the side surface, not bases.
Can I Find Volume Too?
Yes, the calculator includes volume.
Does It Work for Pyramids?
Yes, square and rectangular ones.
Is the Calculator Accurate?
Yes, with correct inputs.
Final Words
The Frustum Surface Area Calculator is a powerful and easy tool for finding the area and volume of truncated shapes. It saves time, avoids math mistakes, and provides reliable results.
Whether you are studying geometry, designing products, or planning a construction project, this calculator helps you measure frustums accurately and confidently.
