Fence Calculator
Fence Layout
Material Preferences
Includes standard formulas estimating 2 bags of concrete per structural support post, plus automatic safety tolerances for section termination posts.
Fence Calculator: How Many Posts, Panels, and Bags of Concrete Do You Need?
Fence projects have more moving parts than most landscaping materials — posts, panels or pickets, gate hardware, and concrete footings all need to be counted separately. Our free fence calculator takes your fence length, height, type, and post spacing, then instantly estimates every component you'll need, plus a full cost estimate including labor, tax, and delivery.
How the Fence Calculator Works
Post count depends on your total fence length divided by your post spacing, plus a starter post and two extra posts for each gate opening. Panel, picket, or rail count depends on your fence type — privacy and chain-link fencing use one panel per spacing section, picket fencing is based on individual picket spacing, and split rail uses a fixed number of rails per section. Concrete footings are estimated at two 50 lb bags per post. Our calculator adds all of this up, then multiplies by your local material prices to build a full cost estimate — including labor time, sales tax, and delivery fees.
Why This Calculator Has an Adjustable Waste Buffer
This calculator applies the adjustable waste buffer on top of your raw calculated panel, picket, or rail count. Fence lines rarely run in perfectly even multiples of your spacing, and cutting panels or pickets to fit corners, gates, and slopes creates offcuts you can't reuse — this buffer covers that so you're not stuck ordering a small top-off batch that may not match your original run in color or finish.
If your fence run is a simple, level, straight line with no gates or corners, or you'd rather order closer to the exact number, you can adjust the waste buffer percentage directly on this calculator — set it anywhere from 0% to 50% to match your comfort level. Note that post count and concrete footings are calculated from the fixed geometry of your layout and aren't affected by the waste buffer — only the purchased panel, picket, or rail material scales with it.
Post Spacing Guide (By Fence Type)
| Fence Type | Typical Post Spacing | Notes |
|---|---|---|
| Privacy / wood panel | 6–8 ft | Matches standard panel widths |
| Picket | 6–8 ft | Pickets themselves are spaced much closer |
| Chain link | 8–10 ft | Can span slightly wider than wood |
| Split rail | 8–10 ft | Fewer posts needed per linear foot |
How Much Concrete Do Fence Posts Need?
Most fence posts are set with two 50 lb bags of concrete mix per post hole. Taller fences, heavier gates, or posts in loose or sandy soil sometimes need additional concrete or a wider hole for stability — check your local frost line depth as well, since posts in colder climates often need to be set below it to prevent heaving.
Frequently Asked Questions
How many fence posts do I need for 100 feet of fence?
At a standard 8 ft spacing, 100 feet of fence needs about 13 to 14 posts (100 ÷ 8, plus one starter post), before accounting for any gates, which each add two additional posts.
What is a good waste buffer for fence panels?
5-10% is a practical range for cuts around gates, corners, and slopes. A simple, straight, level fence line can stay near 5%, while yards with multiple corners or significant slope often belong closer to 10%.
How much concrete does one fence post need?
Most residential fence posts use two 50 lb bags of concrete mix per hole. Larger posts, taller fences, or gate posts carrying more weight may need additional concrete.
How deep should fence post holes be?
A common rule of thumb is burying about one-third of the total post length, though local frost line depth should also guide this — in colder climates, posts often need to be set below the frost line to prevent winter heaving.
How much extra material should I order for a gate?
Each gate typically adds two extra posts to support the hinges and latch, plus a flat allowance for gate hardware. Standard gate openings are commonly 3 to 4 feet wide.
Related Calculators
Planning a full landscaping project? These calculators pair well with fencing:
Retaining Wall Calculator — plan a wall to grade a slope before setting your fence line.
Concrete Calculator — estimate concrete footings for setting fence posts.
Slope / Grade Calculator — check the grade of your yard before laying out a fence line.