Cleanroom Classification

ISO 14644-1 Classification Calculator

Determine the ISO classification of a cleanroom from measured airborne particle counts at 0.5 µm and 5.0 µm.

How ISO Classification Works

ISO 14644-1 defines cleanroom classes based on the maximum permitted concentration of airborne particles at specified sizes. The class limit at any particle size D is calculated using a standard formula, and a room is classified at the lowest ISO class where its measured particle counts, at every measured size, do not exceed the class limit.

Cn = 10^N × (0.1 / D)^2.08 Where: Cn = maximum concentration (particles/m³) at particle size D N = ISO classification number D = particle size (µm)

Interactive Calculator

Measured ≥0.5 µm Particles (per m³)

Measured ≥5.0 µm Particles (per m³)

Determined Classification

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ISO Class Limits Reference

ISO Class	≥0.5 µm Limit (particles/m³)	≥5.0 µm Limit (particles/m³)	Common GMP Grade Equivalent

This tool applies the standard ISO 14644-1 formula for educational and preliminary assessment purposes. Formal classification requires sampling per the standard's defined methodology (number and location of sampling points based on room area, minimum sample volume, and instrument calibration) — confirm your monitoring plan and equipment meet these requirements before using results for room qualification or release decisions.