Indoor Air Quality Score Calculator

IAQ assessment from CO2, VOC, humidity, and particulates.

CO₂ level (ppm)

PM2.5 (µg/m³)

Total VOCs (µg/m³)

Relative humidity (%)

Temperature (°C)

Tab to move between fields

Overall IAQ score (0–100)

CO₂ sub-score85.7

PM2.5 sub-score80

TVOC sub-score96.4

Humidity sub-score100

Temperature sub-score100

Rating (1=Poor, 4=Excellent)4

How to Use This Calculator

How the result changes with CO₂ level (ppm)

CO₂ level (ppm): Carbon dioxide concentration in parts per million. Outdoor ambient is ~420 ppm.
PM2.5 (µg/m³): Fine particulate matter concentration. EPA annual standard is 12 µg/m³.
Total VOCs (µg/m³): Total volatile organic compounds. Target below 500 µg/m³.
Relative humidity (%): ASHRAE recommends 30–60% relative humidity.
Temperature (°C): Indoor temperature. ASHRAE 55 comfort range is 20–26°C.

Overall IAQ score (0–100): Weighted composite score. 80+ = Excellent, 60–79 = Good, 40–59 = Fair, <40 = Poor.
CO₂ sub-score: Score based on CO2 vs ASHRAE 62.1 target of <1000 ppm.
PM2.5 sub-score: Score based on EPA NAAQS annual PM2.5 standard.
TVOC sub-score: Score based on VOC concentration guidelines.
Humidity sub-score: Score based on ASHRAE 30–60% RH range.
Temperature sub-score: Score based on ASHRAE 55 thermal comfort.
Rating (1=Poor, 4=Excellent): 1 = Poor, 2 = Fair, 3 = Good, 4 = Excellent.

Identify Input Parameters
4 parameters
CO₂ level (ppm) = 800, PM2.5 (µg/m³) = 10, Total VOCs (µg/m³) = 300, Relative humidity (%) = 45 = 5 input(s) provided
Calculate Overall IAQ score
Overall IAQ score = co2Score * weights.co2 +
89 = 89
Calculate CO₂ sub-score
CO₂ sub-score = co2Ppm <= 600 ? 100
85.7 = 85.7
Calculate PM2.5 sub-score
PM2.5 sub-score = pm25 <= 0 ? 100
80 = 80