One Reading, Eight Scales

Enter a raw pollutant concentration and instantly see how it maps to air quality indices across the US, China, India, UK, Australia, Singapore, Canada, and Hong Kong.

8
AQI Scales
8
Pollutants
Zero
Dependencies
100%
Free & Open Source

Why This Exists

Air purifiers and sensors display raw concentration numbers like PM2.5 = 35 µg/m³ — but that number means different things depending on where you live.

In the US that's "Good" air. In India it's "Satisfactory." In the UK it's a 4 out of 10. This tool shows you how the same reading is classified across every major standard, side by side.

Features

A focused tool that does one thing well — convert pollutant readings across international AQI standards.

8 International Scales

US EPA, China MEP, India NAQI, UK DAQI, Australia, Singapore PSI, Canada AQHI, and Hong Kong AQHI — all in one view.

8 Pollutants

PM2.5, PM10, O₃ (8h & 1h), CO, SO₂ (1h & 24h), and NO₂. Covers all the pollutants tracked by major air quality indices.

Instant Results

Type a concentration value and see all 8 AQI conversions update in real time. No loading, no server calls.

Health Advisories

Each result is color-coded by risk level with health advisory text, so you know what the numbers actually mean.

Breakpoint Tables

Reference tables showing the exact concentration ranges and AQI breakpoints for each scale and pollutant.

Zero Dependencies

Pure HTML, CSS, and JavaScript. No frameworks, no build tools, no tracking. Runs entirely in your browser.

Check Your Air Quality Now