Fence Post Depth & Cost Calculator
Estimated Total Cost
$294 – $497
$42.00 – $71.00 per post (installed)
Posts Needed
7
Post Depth
24" (2 ft)
Bags / Post
3 bags
Total Bags (50 lb)
21 bags
Post Hole Specs: Dig each hole 10" diameter × 24" deep. Use 8 ft posts (6 ft above ground + 24" buried). Set posts in concrete with 1–2" above grade sloping away from the post for drainage.
Frost Line Note: In cold climates, post depth should extend below the frost line (24–48" in northern states). Our 24" recommendation works for most of the US, but check your local frost depth and building codes.
Note: Most fence contractors charge a minimum of $500 for post installation due to equipment and mobilization costs. Your actual cost may be higher than calculated for small projects.
Disclaimer: Estimates are for budgeting purposes only. Actual costs vary by location, contractor, material availability, and project complexity. Always get professional quotes for exact pricing.
Fence Post Cost Breakdown
| Post Size | Post Lumber | Concrete | Labor | Total / Post |
|---|---|---|---|---|
| 4×4 (8 ft post) | $12 – $20 | $15 – $21 (3 bags) | $15 – $30 | $42 – $71 |
| 6×6 (8 ft post) | $24 – $40 | $25 – $35 (5 bags) | $15 – $30 | $64 – $105 |
* Based on 6 ft fence height (24″ post depth). Costs include post lumber, concrete, and labor.
Average Project Costs (4×4 Posts, 8 ft Spacing)
| Project | Length & Height | Posts | Bags (50 lb) | Estimated Total |
|---|---|---|---|---|
| Garden Fence | 80 ft × 4 ft | 11 | 33 | $429 – $726 |
| Standard Privacy | 50 ft × 6 ft | 7 | 21 | $294 – $497 |
| Privacy Fence | 150 ft × 6 ft | 19 | 57 | $798 – $1,349 |
| Full Perimeter | 300 ft × 6 ft | 38 | 114 | $1,596 – $2,698 |
How We Calculate
Our fence post depth calculator estimates the number of posts, recommended depth, concrete needed, and total project cost based on your fence length, height, post size, and spacing.
How the math works: Number of posts = floor(fence length ÷ spacing) + 1. Post depth follows the 1/3 rule: bury at least one-third of the total post length, with a minimum of 24 inches. Concrete volume per hole is calculated as the cylinder volume (π × r² × depth) minus the square post volume, then divided by 0.375 cu ft per 50 lb bag.
Post Size Comparison
4×4 Posts ($1.50–$2.50/linear ft) are standard for most residential fences. Actual dimensions are 3.5” × 3.5”. Dig a 10-inch diameter hole for proper concrete coverage around the post.
6×6 Posts ($3.00–$5.00/linear ft) are heavy-duty posts for gate posts, corners, tall fences, and high-wind areas. Actual dimensions are 5.5” × 5.5”. Dig a 14-inch diameter hole. Recommended for all 8-foot fences.
Depth Guidelines
For 4–6 foot fences, 24 inches of depth is standard and meets building codes in most areas. For 8-foot fences, increase to 36 inches. In frost-prone regions, the bottom of the post should reach below the frost line to prevent heaving. Check your local frost depth — it ranges from 12” in the southern US to 48”+ in northern states.
Concrete Calculation
Each 50 lb bag of fast-setting concrete fills approximately 0.375 cubic feet. We calculate the hole volume as a cylinder, subtract the post volume, and round up to whole bags. For a 4×4 post in a 10” hole at 24” depth, that’s about 0.92 cubic feet of concrete — 3 bags per post.
Additional Cost Factors
Our estimates include post lumber, concrete, and post-hole labor but do not include fence panels or pickets ($5–$25 per linear foot), rails ($2–$5/LF), hardware and fasteners ($50–$150 total), gate assemblies ($150–$600 each), or property survey and permit fees. Post hole auger rental runs $40–$60/day and can save significant labor time.
Data Sources
Pricing data is compiled from HomeAdvisor, Angi, home improvement retailers, and verified contractor estimates across multiple US regions. Post depth guidelines follow IRC (International Residential Code) recommendations and local building code standards.
Last updated: 2026-02-02
Frequently Asked Questions
How deep should a fence post be? +
The general rule is to bury 1/3 of the total post length underground. For a standard 6-foot privacy fence, set posts 24 inches (2 feet) deep using 8-foot posts. For 8-foot tall fences, use 36 inches of depth. In cold climates, post depth should reach below the frost line (24–48 inches in northern states).
How much does it cost to install fence posts? +
Fence post installation costs $42–$105 per post including materials and labor. A standard 4×4 post with concrete runs $42–$71 per post, while heavy-duty 6×6 posts cost $64–$105 each. Labor alone is $15–$30 per post hole for digging, setting, and plumbing the post.
How many bags of concrete do I need per fence post? +
A 4×4 post set 24 inches deep in a 10-inch hole needs 3 bags of 50 lb concrete. A 6×6 post in a 14-inch hole needs 5 bags. For 8-foot fences with 36-inch depth, 4×4 posts need 4 bags and 6×6 posts need 7 bags each.
How far apart should fence posts be? +
Standard residential fence posts are spaced 8 feet apart (on center). Use 6-foot spacing for heavy-duty fencing, windy areas, or tall fences. Never exceed 8 feet between posts — wider spacing causes sagging and reduces fence lifespan.
Should I use concrete for fence posts? +
Yes, concrete is recommended for all fence posts. It prevents leaning, resists wind loads, and extends post life by 5–10 years. Use fast-setting concrete for DIY projects — pour dry mix into the hole around the post, then add water. Posts are firm in 20–40 minutes.
What size post do I need for a 6-foot fence? +
A 4×4 post is standard for most 6-foot privacy fences. Use 6×6 posts for gate posts, corner posts, end posts, fences in high-wind areas, or heavy fence materials like composite or wrought iron. Always use 8-foot posts for 6-foot fences (6 ft above ground + 2 ft buried).
Can I install fence posts myself? +
Yes, fence post installation is a common DIY project. You’ll need a post hole digger or auger ($40–$60 rental), a level, stakes and string for alignment, and fast-setting concrete. Budget 20–30 minutes per post. A two-person team can set 10–15 posts in a day.
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