Slant Height Calculator
Calculate the slant height of a cone or pyramid from its dimensions.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Slant Height Calculator
Select a shape (cone or pyramid), enter the required dimensions, and the calculator computes the slant height.
- Select the shape. Choose "Cone" or "Pyramid" from the dropdown.
- Enter dimensions. For a cone, enter the radius and height. For a pyramid, enter the height and base side (or radius).
- Read the result. The slant height appears instantly.
For a cone: slant height = sqrt(r^2 + h^2). For a pyramid: slant height = sqrt(h^2 + (s/2)^2), where s is the base side length.
About Slant Height
The slant height is the distance measured along a lateral face from the base to the apex. It is different from the vertical height, which is measured perpendicularly. Slant height is needed to calculate lateral surface area and is found using the Pythagorean theorem applied to a right triangle formed by the height, the slant height, and the base distance (radius or half of a base side).
Frequently Asked Questions
What is slant height?
Slant height is the distance from the apex of a cone or pyramid to a point on the edge of the base, measured along the surface. It is the hypotenuse of the right triangle formed by the height and the base distance.
How do you find the slant height of a cone?
Slant height = sqrt(r^2 + h^2), where r is the base radius and h is the vertical height. This is a direct application of the Pythagorean theorem.
Why is slant height important?
Slant height is required to calculate the lateral surface area of cones and pyramids. Without it, you cannot find the total surface area.