Moment of Inertia Calculator
Find the second moment of area of the most common shapes with our moment of inertia calculator.

What Moment of Inertia Calculator does
The Moment of Inertia Calculator on Omni Calculator determines the second moment of area for common geometric shapes, providing precise values that describe how area is distributed relative to an axis. Users input dimensions for shapes like rectangles, circles, triangles, and hexagons to obtain Ix and Iy values in meters to the fourth power, essential for structural engineering and physics applications. The tool simplifies complex calculations of resistance to bending or twisting forces. Beyond basic computation, the site offers formula explanations and contextual guidance, helping users understand how the calculations work rather than just outputting a number. It also distinguishes between area moment of inertia and mass moment of inertia, linking to a separate calculator for the latter. The interface supports both learning and quick validation of design parameters.
How to use the Omni Calculator Moment of Inertia Calculator
- 1
Select the desired shape from the Shape dropdown menu
- 2
Enter the Width (b) and Height (a) dimensions for the chosen shape
- 3
View the calculated Ix and Iy values representing the second moment of area about the horizontal and vertical axes
- 4
Review the provided formula descriptions to understand the underlying mathematics
Best for
Engineers, architects, and physics students who need to quickly calculate and validate the second moment of area for common structural shapes during design or analysis work.
Limitations
- Results are estimates based on ideal geometric dimensions without material properties
- Primarily designed for area moment of inertia; separate tool needed for mass moment of inertia
- No unit switching available within the calculator interface
Moment of Inertia Calculator FAQ
- What is the difference between area moment of inertia and mass moment of inertia?
- The area moment of inertia is a geometrical property describing how area is distributed about an axis, used in beam bending calculations, while the mass moment of inertia measures an object's resistance to rotational acceleration and depends on mass distribution, expressed in kg·m² or lb·ft².
- Can this calculator handle irregular or custom shapes?
- No, the tool only supports common geometric shapes such as rectangles, circles, triangles, semicircles, ellipses, and regular hexagons. Irregular shapes require manual calculation or specialized software.
- What units are used for the moment of inertia results?
- The results are provided in meters to the fourth power (m⁴) for the area moment of inertia, which is the standard unit for structural engineering applications.
- How do I know which axis to use, Ix or Iy?
- Ix refers to the moment of inertia about the horizontal axis, while Iy refers to the vertical axis. The calculator assumes width is along the x-axis and height along the y-axis, so select the axis relevant to your structural orientation.
More Moment of Inertia Calculator tools
Similar tools
Based on shared tags