How do you accurately estimate the painting expenses for a Bedroom in Biel with excluding ceilings, 1 doors, and 2 windows, covering an area of 10m x 10m?

Accurately estimating the painting expenses for a Bedroom in Biel with excluding ceilings, 1 doors, and 2 windows, covering an area of 10m x 10m, has a price tag of CHF 523.00.

*) 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.