Unit conversion tool
for Compressed Air & Nitrogen
Use the tabs below to convert capacity (Nm³/hr to SCFM, Sm³/hr to Nm³/hr, and normal flow (Nm³/hr) to actual flow (m³/hr), pressure (bar, psi, Pascal) and temperature (°C, °F, Kelvin).
All values use a decimal point and comma-separated thousands (1,000,000.00), the standard notation in our industry. Need help sizing a compressor or nitrogen generator? Our engineers are happy to calculate it with you.
Gas flow can be expressed at different reference conditions. Which reference is used determines how much gas a cubic meter actually contains, so comparing capacities only makes sense once every value uses the same reference.
Important: Mixing up these units is one of the most common causes of incorrectly sized compressed air and nitrogen installations. Always check which reference condition a datasheet uses before comparing capacities.
Both express gas flow at a fixed reference condition, but at different temperatures. Nm³/hr is referenced to 0 °C, Sm³/hr to 15 °C.
Divide the value in Nm³/hr by 1.608.
Example:
To convert SCFM to Nm³/hr, multiply by 1.608.
Actual flow is the real volume of gas passing through a pipe or vessel per hour at the actual operating pressure and temperature. Higher pressure compresses the gas into a smaller volume, higher temperature expands it.
Pressure can be expressed in many different units, depending on the industry, region, or application. Common pressure units include bar, psi, kPa, MPa, and kg/cm².
It is important to distinguish between gauge pressure and absolute pressure:
Bar is the most commonly used pressure unit in Europe, while psi (pounds per square inch) is widely used in North America. Industrial systems may also specify pressure in kPa or MPa, particularly in engineering and process applications.
Important: Always verify whether a pressure value is expressed as gauge pressure (g) or absolute pressure (a). Confusing these references can lead to incorrect calculations, equipment selection, and system performance issues.
Bar(g) (gauge pressure) is measured relative to atmospheric pressure.
Bar(a) (absolute pressure) is measured relative to a perfect vacuum.
At sea level:
Multiply the pressure in bar by 14.5037.
Example:
To convert psi to bar, divide by 14.5037.
Both are metric pressure units:
MPa is typically used for higher-pressure industrial applications, while kPa is common for lower-pressure measurements.
The preferred pressure unit depends on your industry and location:
When comparing specifications, always ensure the pressure values use the same unit and reference (gauge or absolute).
Temperature is measured using different scales around the world, with Celsius (°C), Fahrenheit (°F) and Kelvin (K) being the most common. Accurate temperature conversion is essential in engineering, industrial processes, scientific calculations, and international specifications.
Important: When performing gas flow, thermodynamic, or process calculations, always verify which temperature scale is specified. Using an incorrect temperature unit can lead to significant calculation errors.
Both scales measure temperature, but they use different reference points and increments.
Conversions:
Kelvin is the absolute temperature scale used in scientific and engineering calculations.
Key reference points:
Unlike Celsius and Fahrenheit, Kelvin values are expressed without the degree symbol.
Simply add 273.15 to the Celsius temperature.
Example:
To convert Kelvin to Celsius, subtract 273.15.
Gas volume, pressure, and density calculations are based on absolute temperature. For this reason, engineering standards and gas laws use Kelvin (K) rather than Celsius or Fahrenheit.
Using Kelvin ensures accurate calculations when converting between Normal, Standard, and Actual flow conditions.
The preferred temperature unit depends on your application:
When comparing specifications or performing calculations, always ensure all temperatures are expressed in the same unit.
Do you have a question about our products or services? Feel free to contact us at any time. We would love to hear from you!
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