Fence costs are calculated as a cost per linear foot. The easiest way to estimate the cost is to determine the cost of a single fence panel and then multiply that cost times the number of panels required to achieve the total length of the fence.First, measure the perimeter of the area to be enclosed – while doing this make note of any special situations that will influence to cost such as gate(s) or difficult terrain. If a fence already exists that will be replaced with new materials then simply count the number of fence panels that are present. Wood privacy fences are almost always spaced with posts 8 foot apart on center (this means the measurement from the center of one post to the center of an adjacent post is 8 feet) but always measure to confirm.Lumber is available in standard 8 foot lengths and offers a balanced solution of cost and strength.Spans longer than 8 feet will likely have problems with sagging unless the 2×4 cross beams are upgraded to 2×6 dimension – this also changes the appearance of the fence panel.Spans shorter than 8 feet are usually not necessary, the fence will be stronger but materials cost increase substantially.If there is a need to set the posts at some other length, be sure to choose an increment of 2 feet (i.e. 6 foot, 8 foot, 10 foot, 12 foot etc… ) otherwise installation will require every cross beam to be cut to length.What about the premade panels available at the local home improvement store? These premade panels are often made from pressure treated pine with three cross beams that are 1.5×2.25 inches and frequently sag after installation. The cheap fence panels can be suitable for urgent repair purposes but are not recommended for use when installing a new or replacement fence.Wood fence posts must be pressure treated and rated for ground contact. Galvanized steel fence posts offer longer life after a higher initial cost for the post and the post rail brackets that are required. Many homeowners dislike the appearance of the steel posts but this can be overcome by a simple coat of paint or wrapping the steel post in a wood enclosure.The fence rails should be 2×4 lumber from pressure treated pine or cedar wood. The style of privacy fence and the choice of wood used on the pickets will have the biggest impact to the aesthetics of the wood privacy fence installation. The basic privacy fence consists of 3.5 inch wide dog-eared pickets placed on one side of the rails; this style requires 24-25 pickets between each post. Another option is to use the wider 5.5 inch pickets which requires 16-17 pickets between posts that 8 feet apart. After the measurements are made, it is time to choose the materials for your fence.With this information, the total materials cost for wood privacy fence installation can be put into the fence cost calculator. Using the typical selections that make up more than half of all privacy fences in the US:· 8 foot UC4A pressure treated pine 4×4 wood post (quantity: 1, approx. $8 ea.)· 8 foot UC3B pressure treated pine 2×4 wood fence rails (quantity: 2, approx. $4 ea.)· 6 foot 3.5 inch wide western red cedar pickets (quantity: 24, approx. $2 ea.)· 3 ½ inch 16d galvanized ring shank nails (quantity: 8, approx. $1)· 1 ¾ inch galvanized ring shank nails (quantity: 100, approx. $1)· 1.5 cubic feet of crushed gravel (quantity: 1, approx. $5)This brings the cost of the typical wood privacy fence installation to approximately $71 per panel, or just below $9 per linear foot. Other common fence designs will increase the cost from this baseline estimate of the privacy fence cost. The good-neighbor fence (where the pickets alternate sides of the fence, either picket by picket or panel by panel), shadowbox fence, and board-on-board fence styles both increase the number of pickets. Cap and trip fence style has the clean look of a uniform top edge between each post with the added cost of the top rail. Lattice top privacy fences of course add the cost of the lattice.This estimate is for materials cost only, if you use a contractor to do the work the total cost of the privacy fence installation project will increase by at least double. Constructing a wood privacy fence is within the capability of the typical homeowner, a solid three day weekend of work with two guys can finish a privacy fence around the typical backyard and use the money saved on refreshments to enjoy a job well done.