Cross Sectional Area Calculator
Calculate the cross-sectional area of common shapes. Useful in engineering, physics, and material science for analyzing wire gauge, pipe dimensions, and structural properties.
Formula
Circle: A = π × r²
Rectangle: A = width × height
Tube: A = π × (R² − r²)
- Cross-sectional area is the area visible when slicing perpendicular to the length
- For circular wires: diameter = 2 × radius
- For rectangular sections: commonly width × height
- For hollow tubes: subtract inner area from outer area
Cross-Sectional Area Examples
Inputs
- Shape: Circle
- Radius / Width: 5 cm
- Height (rect/tube): 5 cm
- Inner Radius (tube): 3 cm
Circle with radius 5 cm: A = π × 5² ≈ 78.54 cm². Rectangle 5×5 cm: A = 25 cm². Tube (outer 5, inner 3): A = π × (25 − 9) ≈ 50.27 cm².
Frequently asked questions
What is cross-sectional area?
Cross-sectional area (CSA) is the area of a shape when sliced perpendicular to its length, important for analyzing material properties and flow rates.
Why does CSA matter?
CSA affects electrical resistance (thicker wire = lower resistance), fluid flow rate, and structural strength. Doubling CSA halves resistance.
How do I find diameter from area?
For circular sections: diameter = 2√(area/π). This calculator shows equivalent diameter for comparison.
What is a hollow tube CSA calculation?
Tube CSA = π × (outer radius² − inner radius²), representing only the material area (not the empty core).