# converting air flow rate between l/min to kg/s

I am calculating the air mass flow rate in kg/s for air in a numerical model, and i want to compare the results with an experimental investigation, the flowmeter unit is l/min. how can I convert l/min to kg/s for air?

• You will need the density which means the temperature. Minutes to seconds is a factor of 60. May 23 at 10:10

Given the density of air at 15 Deg C is 1.225kg/m^3, then

assuming 10 litres/min is 0.1666667 litres per second as there are 60 seconds in 1 minute.

1000 litres is 1.225 kg/m^3 so 1.225/1000*0.1666667 = 0.00025 kg/s.

But do use the density of your flow based on its temperature.

• +1, but worth reiterating what you mentioned in your comment to the question: the correct density must be determined.
– Wasabi
May 23 at 15:03

Density is a function of both temperature and pressure. You can use the ideal gas law to calculate the density of air:

$$\rho=\frac{P}{RT}$$

where $$T$$ is temperature, $$P$$ is pressure, and $$R=287 \frac{J}{kg\cdot K}$$ is the specific gas constant for air. Make sure you use the right units; you'll need temperature in Kelvin and pressure in Pascals.