Isolator Load & Frequency Calculator
Calculate required isolator natural frequency from isolation targets, or verify transmissibility for a given isolator configuration.
A passive vibration isolator attenuates floor disturbances above its natural frequency f_n through the transmissibility T = √[(1 + (2ζr)²) / ((1 − r²)² + (2ζr)²)], where r = f_d / f_n is the frequency ratio and ζ is the damping ratio. Effective isolation begins only when r > √2 and improves as r increases. This calculator has two modes. Forward mode takes a disturbing frequency, a desired isolation percentage, and a damping ratio, then numerically solves for the required f_n, static deflection, and recommends a technology class — elastomeric mounts above 5 Hz, pneumatic isolators from 1.5–5 Hz, or negative-stiffness or active systems below 1.5 Hz. Reverse mode computes transmissibility and isolation for a known isolator given its natural frequency, load, and the disturbing frequency.