Balance Calculator by Balance & Test is a professional-grade toolkit for rotating machinery engineers, vibration
analysts, and balancing technicians. Perform essential rotor balancing calculations quickly and accurately, right from
your phone or tablet.

ISO 21940 Balance Tolerance Calculator
Determine permissible residual unbalance to ISO 21940 standards. Select from all standard balance grades — from G0.4
(precision gyroscopes) to G4000 (slow marine drives). Supports both static and dynamic (2-plane) balancing with
adjustable mass distribution between correction planes when the rotor centre of gravity is offset.

Relocation Test
Validate your balancing equipment and setup with 2-position or 3-position relocation tests. Enter magnitude and angle
readings at each position and the app calculates the mean error vector and true unbalance, with a polar plot showing
all readings, error, and corrected vectors at a glance.

Measurement Uncertainty Analysis
Assess the repeatability of your balancing measurements with statistical analysis based on repeated balance runs.
Supports single-plane and dual-plane rotors. Enter multiple readings and view the mean vector, 95% certainty radius, and pass/fail status against your tolerance limits — all displayed on interactive radar plots.

Additional Features
- Switch between metric (mm, kg, g·mm) and imperial (in, lb, oz·in) units globally
- Clean, intuitive interface designed for use in workshop and field environments
- All calculations performed locally on your device — no internet connection required
- No ads, no tracking, no data collection

Built by Balance & Test Machinery Group — making balancing and testing simpler, more reliable, and more affordable for
everyone.