Painting Job Estimator for Painters. Painting Job Estimator Pro 3 is for interior and exterior. Enter room size or exterior of house size to calculate square footage, perimeter and area. Save your interior and exterior painting estimates and customers data. The application saves your item prices in settings and adds up your painting estimate automatically. It also calculates how much paint and or wallpaper you need to do the job. Paint Job Estimator allows you to accurately bid on a painting project. It also saves your estimates to a file on your SD card or email to yourself or customer.