Free structural engineering tool. Calculate instant deflection, slope, and support reactions for simply supported beams with formulas. Support for point and distributed loads.
Enter the beam length, the Young's Modulus (E) of the material, and the Moment of Inertia (I). For steel, E is typically 200-210 GPa.
Input the applied load (Point load or Uniformly Distributed Load - UDL). Select the support condition: Simply Supported, Cantilever, or Fixed-Fixed.
The tool outputs the maximum deflection (δ) and rotation (θ). Ensure the deflection is within the limits set by building codes (e.g., L/360 for floor beams).
Yes. For long spans, the self-weight of the beam (UDL) can contribute significantly to the total deflection. Our tool allows you to add this as a secondary load.
Deflection is proportional to the cube of the length (L³). Doubling the span length increases the deflection by 8 times, assuming all other variables remain constant.
Yes. Excessive rotation at supports can damage bearings or cause stability issues in connected members. Slope is measured in radians or degrees.
For the same span, load, and section, end restraint changes deflection dramatically. A central point load gives PL³/48EI when simply supported but only PL³/192EI when both ends are fixed — one quarter as much. A cantilever of the same span deflects PL³/3EI, sixteen times the simply supported value, because a single end carries everything.