Exact rotating-frequency arithmetic
Frequency Order Calculator
Convert a measured spectral frequency to shaft order, or convert a target order to frequency. The result is a frequency relationship—not a fault diagnosis or probability.
Frequency relationship
These are dimensional identities: rpm divided by 60 gives cycles per second, and order is the ratio of a component frequency to shaft rotational frequency.
ISO 13379-1:2025 is the current general guideline for data interpretation and diagnostic techniques; it replaced withdrawn ISO 13379-1:2012. Its public scope describes common concepts, technical characteristics and selection/development of an appropriate diagnostic approach. It does not publish this page’s former symptom weights or probability calibration.
ISO 13373-2:2016 covers vibration-data processing, analysis and presentation. ISO 13373-3:2015, confirmed current in 2026, describes a structured approach to vibration diagnosis. This calculator does not implement or certify conformity to either standard.
Removed claims: the former 17-fault matrix assigned undocumented integer weights and displayed score/max as “confidence”. No calibration dataset, likelihood model, false-positive rate or ISO clause supported those percentages, so the diagnostic ranking and fault table were removed rather than presented as probabilities.
