Beam load workflow
Convert the force-per-length units used for uniform and varying beam loads. You can also turn an area pressure into a beam line load using tributary width.
Enter a value in any field
Pressure to line load
Next step
Send the converted line load to the Beam Calculator; the load dialog will be prefilled across the full beam length.
Quick reference
N/mm and kN/m have the same numerical value, a useful identity for beam and finite-element checks.
| From | Equivalent |
|---|---|
| 1 kN/m | 1 N/mm |
| 1 kN/m | 68.5218 lb/ft |
| 1 kN/m | 0.0685218 kip/ft |
| 1 kip/ft | 14.5939 kN/m |
| 1 lb/ft (1 plf) | 0.0145939 kN/m |
| 1 lb/in | 0.175127 kN/m |
Engineering context
A floor or roof load is often specified as pressure, such as psf or kPa. A one-dimensional beam model needs force per length, so multiply the pressure by the tributary width carried by the beam.
Use matching length systems: psf × ft gives plf, while kPa × m gives kN/m. Add dead, live, snow, and other components only after applying the appropriate design method and load combinations.
kg/m describes mass per length. Beam loading is a force per length such as kN/m or lb/ft. Convert mass to weight using gravitational acceleration before applying it as a load.
Where this conversion is used
Questions engineers ask
Yes. Both the force and length change by a factor of 1,000, so the numerical value stays the same.
Multiply kN/m by approximately 68.5218.
plf means pounds per linear foot. In structural load notation it is numerically the same as lb/ft.
Multiply pressure in psf by tributary width in feet. For example, 50 psf over 10 ft gives 500 plf.
Multiply pressure in kPa by tributary width in metres. One kPa is one kN/m², so 4.8 kPa over 3 m gives 14.4 kN/m.
Conversion factors follow SI and U.S. customary unit relationships. Rounded reference values are for convenience; the live converter uses higher-precision factors.