LEV calculations

Convert between Pa, ppm and mg/m³
Enter the molecular weight and the working temperature, and one only of vapour pressure (Pa) or airborne concentration in ppm or mg/m³

This calculator will accept a series of numbers and display the total and average values.
Enter a value, click on the button or hit [Enter] and repeat.

This calculator is optimised for face velocity readings in m/s to 2 decimal places so there is no need to enter a decimal point.

eg A value of 145 will be transposed to 1.45; 26 will become 0.26 etc

To change this, just select an option from the drop-down menu. 0.01 0.10 As is

This calculator will determine the volume flow through a duct.

Note: The duct wall is considered to be of negligible thickness

The volume flow for an air velocity of m/s, through a circular duct with a Circumference Diameter Radius of m

...through a rectangular duct m by m

This calculator will determine the air change rate in a room.
Enter the room dimensions and extract rate and click on the button.

The standard air density at 20°C and 1013mb barometric pressure is 1.2 kg/m³.
Enter a different temperature or pressure value in the appropriate box.

Calculate air velocity, metres/second from pressure difference (Pitot)
The standard air density at 20°C and 1013mb barometric pressure is 1.2 kg/m³.

Enter pressures and any different density value in the appropriate boxes.