Grms Calculator for random vibration testing
Random Vibration — Grms, Peak Displacement & Velocity Calculator
Enter PSD breakpoints manually, adjust segment slopes, or paste a tab/comma-separated table.
PSD Breakpoint Table
Freq (Hz)
PSD (g²/Hz)
Slope↓ dB/oct
Rows 2+ accept either PSD or Slope — entering one calculates the other on Tab/Enter.
Row 1 always requires both Freq and PSD as the anchor.
Paste from Clipboard
PSD Shape
Results
Acceleration (Grms)
—
g RMS
Peak-to-Peak Displacement
—
mm p-p · 3σ
Peak Velocity
—
m/s pk · 3σ
Peak values use 3σ (3× RMS), matching vibration controller convention.
Displacement and velocity are computed by integrating the full PSD spectrum weighted by their transfer functions — the same method used by vibration test controllers.
v1.4
calculate all test modes and with shaker limits
Download RULA Technologies TestUP software to calculate the force, acceleration, velocity and displacement needed for all test modes including sine, random, shock, SRS, sine on random, random on random and more. Select your test type, shaker, test mass and enter the test profile details. The software will calculate the required acceleration, velocity and displacement requirements, and based on the selected shaker system let you know if you’re within the shaker limits. The maximum force is calculated using the test mass vs acceleration values.
This is a free tool. Click the link below to register and download TestUP software today!
