| Inputs |  | 
| Tension | Tension of the web (N/m or lb/in) | 
| Roughness | Combined roughness of roller and web (µm or mil) | 
| Diameter | Diameter of the roller (mm or in) | 
| Thickness | Thickness of the web(µm or mil) | 
| Frict.Coef. | Friction coefficient at low speed | 
| Wrap | Angle of wrap of web around roller(°) | 
| Speed | Web Speed (m/min or ft/min) | 
| Outputs |  | 
| Air gap | Flying height if no grooved roller) (µm or mil) | 
| º Calc | Calculated coeff.frict. due to air gap | 
| TFrac | Fraction of tension available to resist slip | 
| GPitch | Pitch of grooves to remove air (mm or in) | 
| GWidth | Width of grooves to remove air (mm or in) | 
| GDepth | Depth of grooves to remove air (mm or in) |