The seismic resistance of a structure is the maximum earthquake magnitude on the moment magnitude scale (similar to the more famous Richter Scale) which it can sustain without suffering incapacitating damage. This means that no compromising structural damage should occur when the structure sustains an earthquake or other seismic event of the entered magnitude, and that the various elements necessary to continued functioning (such as walls, doors, windows, elevators, mechanical systems, plumbing, and wiring) remain sufficiently intact that no interruption of use is necessary after the shock.

A structure's seismic resistance is almost always a predictive calculation, not tested to the limit through experience. Therefore a small degree of imprecision is expected in this figure.

Moment magnitude describes the size of an earthquake. Local shaking also depends on distance from the rupture and ground conditions, so magnitude alone does not specify the force applied to the structure. The value depends on the conditions assumed in the resistance assessment.