Fence Material Calculator
Estimate posts, sections, rails, pickets, post length, and concrete for a straight fence run using one consistent material plan.
Fence inputs
Live estimate
Material breakdown
| Material / measure | Quantity | Unit | Planning basis |
|---|---|---|---|
| Posts | 14 | pieces | Ceiling(length ÷ spacing + 1) |
| Fence sections | 13 | sections | Posts – 1 |
| Rails | 26 | pieces | 2 per section |
| Pickets | 200 | pieces | Fence length ÷ board module |
| Post length | 9.00 | ft each | 1.5 × fence height |
| Concrete | 1.38 | yd³ total | Footing void around all posts |
Counts are rounded up because partial posts, rails, and pickets cannot satisfy a complete fence run. Add a project-specific waste allowance before purchasing.
How to use the fence material calculator
What this calculator does. It estimates the principal materials for a straight fence: posts, sections, rails, pickets, required post length, buried depth, and concrete around the buried post portions. It is a planning estimator, not a structural design, permit check, property survey, wind-load analysis, or substitute for local code and utility-locate requirements.
When to use it. Use it while comparing fence layouts, preparing a store order, checking how post spacing changes material counts, or estimating concrete before a do-it-yourself installation. It is especially useful when you need one consistent calculation across feet and inches or meters and centimeters.
How to calculate. The calculator opens with a complete 100 ft demonstration fence and an immediately available example XLSX workbook. (1) Choose the Measurement system. (2) Replace Fence length, Post spacing, and Fence height with your measured dimensions. (3) Enter Rails per section, Picket width, and Picket spacing. (4) Choose Post shape and provide either Post width plus Post thickness, or Post diameter. (5) Read the live result cards and material table, then use Download Excel to export the current typed model. Reset clears the demonstration and all entered dimensions; Excel remains unavailable until a complete valid plan is entered again.
Input guide. Fence length is a required positive decimal in feet or meters; 100 ft is the example, and a longer run increases every material count. Post spacing is a required positive distance, commonly near 6 – 8 ft for many residential layouts, but the correct spacing depends on material, loads, and local requirements; entering a larger spacing usually reduces posts. Fence height is the finished above-grade height and drives both post length and embedment. Rails per section is a required whole number from 1 to 10; it multiplies by the section count. Picket width and Picket spacing are required nonnegative board-module dimensions in inches or centimeters; width must be positive, while a zero gap is permitted. Avoid mixing feet with inches or meters with centimeters – the unit labels show what each field expects. Post shape switches the footing model. Rectangular posts require positive width and thickness; round posts require a positive diameter. Dimensions must represent the actual post cross-section, not the hole size.
Output guide. Number of posts is a whole-piece estimate rounded upward. Number of sections is one fewer than the post count for a straight run. Post length equals 1.5 times fence height, and Buried post depth is one-third of that post length. Number of rails is sections multiplied by rails per section. Number of pickets divides the fence run by picket width plus gap and rounds upward. Concrete volume estimates the void between a post and a hole three times the post cross-section dimension. High concrete volume usually means more posts, larger posts, or taller posts; zero is not valid for a complete fence.
Worked example. For the opening 100 ft fence with 8 ft maximum post spacing, the post calculation is ceiling(100 ÷ 8 + 1) = 14, giving 13 sections. Two rails per section produce 26 rails. A 5.5 in picket plus a 0.5 in gap creates a 6 in module; 1,200 in ÷ 6 in = 200, and the formula used by this estimator rounds the full-run ratio upward, producing 200 pickets. A 6 ft fence uses 9 ft posts with 3 ft buried. For 4 in × 4 in rectangular posts, the total footing estimate is 1.38 yd³.
Learn more. Before digging, review the U.S. 811 safe-digging process. For general fence planning and agricultural installation principles, consult the USDA NRCS conservation practice standards. Unit conversions in this tool follow the NIST guidance for SI length units.
How the formulas work
The post count is rounded up from fence length divided by desired spacing, plus one end post. Sections equal posts minus one. Post length is estimated as 1.5 times finished fence height, and buried depth is one-third of that total post length. Rails multiply the number of sections by the chosen rails per section. Pickets use the combined board width and clear gap as one repeating module.
Sections = posts – 1
Rails = sections × rails per section
Pickets = ceiling(fence length ÷ (picket width + picket spacing))
For rectangular posts, the assumed hole is three times the post width by three times the post thickness. Subtracting the buried post volume leaves eight post cross-sections of concrete per unit of depth. For round posts, the corresponding difference between a hole with triple diameter and the post itself simplifies to 2π × diameter² × depth. These are geometric estimates; soil, frost depth, drainage, post type, wind exposure, and local code can require a different footing.
Planning and purchasing notes
Field layouts rarely divide perfectly. Corners, gates, grade changes, terminal posts, decorative spacing, and trimming can alter quantities. Measure the actual fence line, identify every corner and gate, and confirm whether those locations need heavier posts or additional hardware. The estimator intentionally does not add a waste percentage, because appropriate overage varies by material and project. Many installers add a modest allowance for cuts, defects, and repairs after checking supplier pack sizes.
Concrete volume is shown in cubic yards for imperial inputs and cubic meters for metric inputs. Ready-mix suppliers and bagged-concrete products may use different ordering units, so convert the result to the supplier's packaging and round upward. Follow manufacturer instructions for water, mixing, curing, and cold- or hot-weather placement. The Portland Cement Association overview of curing explains why moisture and temperature control matter after placement.