CO₂ ppm ↔ mg/m³ Converter

Convert carbon dioxide readings between ppm and mg/m³ while accounting for actual room temperature and pressure. Adjust the molar mass field to reuse the tool for other gases monitored in indoor air quality programmes.

Enter ppm or mg/m³ depending on mode.
Ambient air temperature.
Local barometric pressure (kPa).
Optional. Default converts ppm to mg/m³.
Optional. Default 44.01 for CO₂.

Assumes ideal gas behaviour. For high concentrations or pressurised systems, consult detailed gas property tables.

Examples

  • 1,000 ppm at 23°C and 101.3 kPa ⇒ 1.836 mg/m³ using 44.01 g/mol.
  • 0.900 mg/m³ at 18°C and 95 kPa, mode 2 ⇒ 516.62 ppm.

FAQ

Do I need to correct for humidity?

For typical indoor humidity levels the effect is minor. For critical environments, adjust the effective molar mass or use a psychrometric calculator to refine the pressure term.

What if my sensor reports in ppm but the standard is mg/m³?

Leave the mode at 1 and enter the ppm reading along with local temperature and pressure to get mg/m³ aligned with occupational standards.

Can I convert other gases like CO or NO₂?

Yes. Replace the molar mass with the target gas (e.g., 28.01 for CO, 46.01 for NO₂) and run the calculation.

Additional Information

  • Conversion uses the ideal gas law with R = 8.314462618 Pa·m³/(mol·K).
  • Inputs accept any gas by changing the molar mass from the CO₂ default of 44.01 g/mol.
  • Pressure should reflect indoor elevation; 101.3 kPa corresponds to sea level conditions.

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