Vibration Unit Converter
Convert between acceleration, velocity, and displacement vibration units at any frequency. Compare specs across vendors or interpret vibration analyzer readings instantly.
Input Parameters
Results
Enter a vibration value, select the unit, and specify a frequency to see all equivalent values.
How Vibration Units Relate
Acceleration, velocity, and displacement describe the same vibration motion from three different perspectives. For a sinusoidal vibration at frequency f, these three quantities are related through calculus: velocity is the integral of acceleration, and displacement is the integral of velocity.
At a given frequency, knowing any one of the three quantities lets you calculate the other two. The relationships are:
Acceleration → Velocity
vpeak = apeak / (2πf)
Acceleration → Displacement
dpeak = apeak / (2πf)²
Velocity → Acceleration
apeak = vpeak × 2πf
Velocity → Displacement
dpeak = vpeak / (2πf)
Displacement → Velocity
vpeak = dpeak × 2πf
Displacement → Acceleration
apeak = dpeak × (2πf)²
These conversions assume pure sinusoidal motion at a single frequency. Real-world vibration signals contain many frequencies, so this converter is most accurate when applied to individual spectral components rather than broadband overall values.
Amplitude Conventions
- Acceleration is typically expressed as peak (zero-to-peak) amplitude.
- Velocity is commonly given as either peak or RMS. ISO standards use RMS. American practice often uses peak. RMS = Peak / √2 for sinusoidal signals.
- Displacement is almost always reported as peak-to-peak (the full swing from maximum positive to maximum negative). Peak-to-peak = 2 × peak amplitude.
Common Reference Values (ISO 10816)
The ISO 10816 standard provides velocity-based vibration severity guidelines. The table below shows thresholds for Class I machines (small machines up to 15 kW):
| Zone | Velocity (mm/s RMS) | Condition |
|---|---|---|
| A | < 0.71 | New or reconditioned |
| B | 0.71 – 1.8 | Acceptable for long-term operation |
| C | 1.8 – 4.5 | Tolerable only for limited periods |
| D | > 4.5 | Damage likely — immediate action required |
For larger machines, the thresholds shift higher. Class II (15–75 kW): Good < 1.8, Acceptable < 4.5, Alert < 11.2. Class III/IV (rigid/flexible foundation, >75 kW): Good < 2.8/4.5, Acceptable < 7.1/11.2.
When to Use This Converter
- Comparing vendor specs: One sensor datasheet lists sensitivity in g, another in mm/s². Convert to compare directly.
- Interpreting analyzer readings: Your vibration analyzer shows acceleration, but alarm thresholds are in velocity RMS. Convert at the frequency of interest.
- Sensor selection: Accelerometers measure acceleration natively. Convert to expected displacement or velocity at your machine’s running speed to verify sensor range.
- Reporting: Convert between units used by different teams, standards, or reporting systems.
For more in-depth bearing vibration analysis techniques and practical monitoring guidance, visit iotbearings.com.