CO2 in Room Calculator
Estimate CO2 levels in a room based on volume, occupants, and ventilation rate.
Check if your indoor air quality is healthy.
Estimated CO2 Level
CO2 concentration in a room depends on room volume, number of occupants, and ventilation.
CO2 (ppm) = Outdoor CO2 + (Occupants × CO2 per Person × Time) / (Room Volume × Ventilation Rate)
At steady state: CO2 = Outdoor CO2 + (n × G) / Q
Where n = occupants, G = CO2 generation rate, Q = ventilation rate.
CO2 levels and health effects:
- Outdoor air: ~420 ppm
- Good indoor: <800 ppm
- Acceptable: 800–1,000 ppm
- Stuffy/drowsy: 1,000–2,000 ppm
- Headaches/fatigue: 2,000–5,000 ppm
- Dangerous: >5,000 ppm
Human CO2 production:
- Resting/sitting: ~0.2 L/min per person
- Light activity: ~0.4 L/min per person
- Moderate activity: ~0.8 L/min per person
ASHRAE recommends a minimum of 15 CFM (7.5 L/s) of outdoor air per person for offices.