Stress Calculator

Force vs. Area

If an elephant steps on your foot wearing a flat sneaker, it hurts. If an elephant steps on your foot wearing a razor-sharp high heel, it pierces straight through your foot.

The physical weight (Force) of the elephant never changed. What changed was the Area over which that force was applied. This is the fundamental definition of Mechanical Stress ($\sigma$).

Engineering Stress

In structural engineering, you cannot just say "this steel beam can hold 10,000 pounds." A thick beam can hold it easily, but a thin beam will snap immediately.

Engineers must calculate the Stress, which normalizes the force based on the exact thickness (Cross-Sectional Area) of the material.

The Equation

The standard scientific unit for Stress is the Pascal ($Pa$), which is exactly equal to one Newton of force spread perfectly over one square meter of area. Because a Pascal is so incredibly weak, engineers almost exclusively use MegaPascals ($MPa = 1,000,000\ Pa$).