Normal Force Calculator
Calculate the normal force acting on an object resting on a flat or inclined surface.
What is normal force
The normal force is the support force exerted by a surface, acting perpendicular to that surface, which prevents an object from passing through it. On a flat horizontal surface it equals the object’s weight; on an incline it equals only the component of weight perpendicular to the surface.
How this calculator works
Enter the object’s mass and the angle of the surface from horizontal (0° for a flat surface). The calculator computes N = mg·cos(θ), using standard gravity, and adds any extra downward force you specify (such as someone pressing down on the object).
This calculator assumes the surface is rigid and the object is in equilibrium perpendicular to the surface, with no other vertical forces besides gravity and the optional applied force. For general physics education purposes.