Conical Frustum Calculator

    Solve a right circular conical frustum from radii or diameters and height, slant height, volume, or lateral area.

    Enter all linear dimensions in one unit. If you measured diameters, switch the base measurement type and the calculator will convert them to radii before solving.
    Open container and material

    Use lateral area for a lampshade or open shell, lateral area plus one base for buckets and planters, and total area for a closed solid.

    enter values for an exact diagram
    Height: 2.4Slant heightBottom radius: 2Top radius: 1

    Full conical frustum solver

    This page covers the broader English intent behind frustum calculator and truncated cone calculator. It accepts radii or diameters, then solves for volume, slant height, lateral area, total area, and material-oriented area combinations.

    Known valuesSolved values
    Radii and heightVolume, slant height, areas, angles, and axial section.
    Radii and slant heightHeight and all dependent outputs.
    Radii and volumeHeight and the full geometry.
    Radii and lateral areaSlant height, height, and volume.

    Material area decisions

    Open containers, planters, funnels, and lampshades rarely need the same area. The calculator shows lateral area, total area, lateral plus bottom base, and lateral plus top base so the result can match the real task.

    R and r are base radii, and s is slant height.

    Total area includes both circular bases.

    Sheet-metal patterns, seam allowances, thickness, and manufacturing tolerances are outside the basic geometry model.

    Frequently Asked Questions

    Sources and References

    Calculations are based on the listed reference sources. Links open in a new tab.

    Updated:

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