We’ve built a comprehensive, free vibration engineering calculator and made it available directly on our website — no login, no download, no strings attached.
At KDP, we work with engineers every day who need quick, reliable answers to vibration questions — whether they’re commissioning a new motor, troubleshooting a pump, specifying a sensor, or verifying a cable run. The tools they reach for are often outdated, incomplete, or locked behind paywalls. We wanted to do something about that.
The result is the KDP Vibration Calculator: a single-page engineering tool that covers the calculations a reliability or condition monitoring engineer actually needs, built to the standards they work to.
What it covers
The calculator is organised as a sidebar application with ten tools, all accessible instantly without scrolling or switching between pages.
Acceleration, velocity and displacement conversion at any frequency. RMS, Peak and Peak-to-Peak. Full ISO 10816 severity assessment with colour-coded zone classification against all six machinery groups.
BPFO, BPFI, BSF and FTF from bearing geometry, with Hz and ×RPM multiplier columns. Gear mesh frequency. Running speed harmonics up to 20× with CPM alongside Hz.
Calculate fn from stiffness/mass or static deflection. Critical speed separation margin checker with pass/fail. RPM ↔ Hz converter.
Same-quantity and cross-quantity conversion across all amplitude types and units, including dB levels referenced to ISO 1683 for velocity, acceleration and displacement.
IEPE sensor guidance based on frequency range, vibration level and application — general machinery, motors, pumps, turbomachinery and gearboxes.
Convert loop current to vibration level for any sensor range and zero offset. Loop supply check — calculates minimum voltage required and flags insufficient supplies.
Maximum cable length for IEPE and charge-mode accelerometers from first principles, with a frequency sweep chart showing how maximum length degrades with frequency.
Log dated RMS velocity readings per machine. Chart plots trend over time with ISO severity zone bands overlaid. Export to CSV for reporting.
Permissible residual unbalance per ISO 1940-1 for grades G0.4 through G100, with a reference table covering typical machine types.
Full ISO 10816-3 velocity limits for all six machinery groups, key conversion formulas and bearing fault frequency equations — all in one place.
Every tool loads with a realistic worked example pre-filled — a 1500 RPM motor running at a Good severity level — so you can see live results the moment you open the page.
Built for engineers, not for demos
A lot of online vibration calculators are marketing tools that happen to do one conversion. They’re useful for a quick sanity check but stop short of what an engineer in the field actually needs. We set out to build something closer to a working reference tool.
The ISO 10816 severity assessment is implemented across all six machinery groups — not just the three most common ones. The bearing fault calculator outputs both Hz and shaft-order multipliers, because engineers think in both. The cable length calculator derives its result from first principles, so it works for any combination of current source, capacitance and frequency.
The crest factor calculator takes separate peak and RMS inputs rather than assuming a pure sine wave, because real machinery signals aren’t sinusoidal — and a CF of 4.0 on a real bearing tells you something very different from the theoretical √2 of a clean signal.
Standards covered
ISO 10816-3 — Mechanical vibration, evaluation of machine vibration by measurements on non-rotating parts
ISO 20816 — Mechanical vibration, measurement and evaluation of machine vibration
ISO 1940-1 — Mechanical vibration, balance quality requirements for rotors in a constant (rigid) state
ISO 1683 — Acoustics, preferred reference values for acoustic and vibratory levels
API 670 — Machinery Protection Systems (referenced in proximity probe guidance)
Free to use — no account needed. Open the calculator and start working with your data straight away.
Open the KDP Vibration Calculator →Who it’s for
The tool is aimed primarily at reliability engineers, condition monitoring technicians, maintenance engineers and anyone involved in specifying or commissioning vibration measurement systems. It’s particularly relevant if you’re working with IEPE or 4–20 mA vibration sensors — the sensor selection, cable length and loop current tools were built with that workflow directly in mind.
It will continue to be updated. A version changelog is accessible from within the calculator itself.
For engineering reference only. Always verify against the current published standard before use in formal assessments or engineering decisions.
