How do you calculate the painting expenses for a Hall Room in Biel, excluding ceilings, 2 doors, and 2 windows, measuring 4m x 9m?

Meticulously calculating the painting expenses for a Hall Room in Biel, excluding ceilings, 2 doors, and 2 windows, measuring 4m x 9m, should cost you around CHF 316.00.

*) 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.