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Vibration Velocity to Acceleration and Displacement Converter

Vibration is reported as displacement, velocity or acceleration depending on the frequency range and instrument. This converter changes between them for a single frequency so you can compare a handheld reading with an ISO limit or a sensor datasheet.

Your numbers

Frequency

Running speed in rpm divided by 60 for 1x vibration.

Velocity, RMS

mm/s

Your results

Displacement, peak to peak

40.5142

In micrometres (um).

Acceleration, peak

0.2039

In g.

Velocity, peak

6.364

Peak equals RMS times 1.414 for a pure sine wave.

Acceleration, RMS

0.1442

In g.

Valid for a single sinusoidal component only. Broadband or multi-frequency signals cannot be converted this way.

Save results:

Peak acceleration (g) at constant velocity vs frequency

Sweeps Frequency from 10 to 1000, holding your other inputs fixed.

Condition data next to ERP assets

Optional: discuss linking vibration trends to equipment records and work orders.

Optional. The tool and every export work without this. No spam.

How to use it

Enter the frequency of the component you care about, for example 1x running speed, and the RMS velocity in mm/s. The tool returns peak velocity, peak-to-peak displacement in micrometres and acceleration in g. Use the chart to see why acceleration dominates at high frequency while displacement dominates at low frequency for the same velocity.

The relationships

For a sine wave, velocity is the derivative of displacement and acceleration is the derivative of velocity. That gives v = 2 pi f d and a = 2 pi f v, where d and v are peak values. Peak-to-peak displacement is twice the peak value, and RMS is peak divided by the square root of two. Converting mm/s to m/s and dividing acceleration by 9.80665 gives g.

Displacement is best for low frequency and slow machines
Velocity is the usual choice for general machine condition (ISO 10816 / 20816 bands)
Acceleration is best for high frequency and bearing defects

Common mistakes

The most common error is mixing RMS, peak and peak-to-peak. A limit quoted as mm/s RMS is not the same number as the peak reading shown by some meters. Another is applying single-frequency conversion to a broadband overall value, which is not valid. Always record the unit and the detector type next to every reading in your route data.

Comparing a peak reading with an RMS alarm limit
Using rpm instead of Hz in the formula
Converting an overall value that contains many frequencies

Frequently Asked Questions

How do I convert mm/s to g?

For one frequency, acceleration in g equals 2 x pi x f x velocity in mm/s divided by 1000 and divided by 9.80665. Use the same detector type, RMS or peak, on both sides of the conversion.

Why does acceleration rise with frequency?

Acceleration is proportional to frequency times velocity. At the same velocity, a 1000 Hz component has twenty times the acceleration of a 50 Hz component.

What is the RMS to peak ratio?

For a pure sine wave the peak is 1.414 times the RMS value. Real machine signals with several components have a crest factor that differs, so do not apply this to overall values.

Can I use this for ISO 10816 limits?

Yes for comparing units at a single frequency, but ISO bands apply to broadband RMS velocity, typically 10 to 1000 Hz. Compare overall RMS velocity directly with the band for your machine class.

If your condition monitoring readings live in spreadsheets or a historian, Netray can bring them next to ERP asset and work order data for trend review.

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