How do you determine the precise painting service cost for a Living Room in Biel, considering excluding ceilings, 2 doors, and 1 windows, with dimensions of 4m x 4m?

Determining the precise painting service cost for a Living Room in Biel, considering excluding ceilings, 2 doors, and 1 windows, with dimensions of 4m x 4m, it turns around a cost of CHF 189.00.

*) The calculations are approximate, based on a room height of 2.4m, and include one coat of paint. The price covers only the labor, excluding any services or materials.