Cost 8 foot fence picket can vary greatly depending on several factors: Obviously. The size of the area to be fence is the single largest factor. That determines the cost of installing a fence (all other factors being equal). Most wooden fences are install in 8 parts of the foot so that measuring. The circumference of the property using a tape measure tape or surveyor wheel and dividing it by 8. Skip the distance to get a rough estimate or for the fence. That has an existing fence post and measure 1-panel length. The height of the fence will also have a major impact on costs.