Fence Calculator
100 ft of 6 ft pine privacy fence with one 4 ft gate takes 14 posts, 36 rails, 218 pickets and 58 bags of 50 lb concrete mix. Change any size or option and the list follows.
Your plan
- 14postsPosts: line, end and gate
- 36rails
- 218pickets
- 58bags50 lb bags of concrete mix
100 ft of 6 ft pressure-treated pine privacy fence: 14 posts, 36 rails, 218 pickets
Example changePost spacing 8 ft → 6 ft: +4 posts, +12 rails, +17 bags of concrete, +2 bags of gravel
Shopping list
6 items- 9 ft pressure-treated pine 4x4 posts6 ft above ground + 36 in in the ground; 1 end, 2 gate, 11 line14 posts
- 8 ft pressure-treated pine 2x4 rails3 per section × 12 sections36 rails
- 6 ft pine pickets, 5 1/2 in wide95.56 ft ÷ 5 1/2 in = 209 + 9 for the gate218 pickets
- 50 lb bags of concrete mix21.68 cu ft in 14 10 1/2 in holes, less the posts ÷ 0.375 cu ft per bag58 bags
- 60 lb bags of all-purpose gravel6 in under each post: 4.21 cu ft ÷ 0.6 cu ft per bag8 bags
- Gate hinge and latch setsOne per 4 ft gate1 set
Check before you build
- The last section is 7 ft 6 3/4 in, shorter than the others (8 ft). Cut its rails and pickets to fit, or turn on equal sections to share the length out.
- The holes are 42 in deep. QUIKRETE fills holes deeper than 2 ft 6 in in lifts, a layer at a time.
- Use hot-dip galvanized or stainless nails and screws in treated wood (Simpson Strong-Tie). The list leaves fasteners to you.
- Gate frames (the rails and the diagonal brace behind the pickets) aren’t in the list: our sources print no frame sizes.
- Call 811 a few days before you dig, so buried lines are marked.
How this is calculated
Counts use your measurements and the assumptions below. References beside an item support its input values or rule, not the finished count.
What moves the answer most
- Post spacing
- 8 ft on centre
- Post depth
- 1/3 of the post's length: 36 in in the ground for a 6 ft fence
Sources QUIKRETE Concrete Mix 1101 data sheet (Oct 2022); Sakrete 5000 Plus Concrete Mix data sheet (2023)
- Hole diameter
- 10 1/2 in
Source QUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- Concrete bags
- 50 lb, 0.375 cu ft each
Sources QUIKRETE Concrete Mix 1101 data sheet (Oct 2022); QUIKRETE Fast-Setting Concrete Mix 1004 data sheet (Nov 2025)
Other assumptions (10)
- Gates
- 1 × 4 ft, at the start of the run
Source Bufftech molded and extruded fence installation guide (2201)
- Gap beside each gate
- 1 in on the hinge side, 3/4 in on the latch side
Source Bufftech molded and extruded fence installation guide (2201)
- Gravel under each post
- 6 in
Source QUIKRETE how-to: Setting Posts without Mixing
- Concrete around the post
- The post's own volume is left out of the hole
Planner setting or your selection; no external document cited.
- Post size
- 4x4, 3 1/2 in actual
Source NIST PS 20-25, American Softwood Lumber Standard (Jan 2025)
- Rails per section
- 3: our default, as no wood-fence maker in our sources prints a count
Planner setting or your selection; no external document cited.
- Picket width
- 5 1/2 in actual
- Gap between pickets
- None, pickets butt together
Planner setting or your selection; no external document cited.
- Pickets
- 70 in needed, 2 in above the ground; bought 6 ft long
Sources Master Halco PostMaster Traditional installation guide; Master Halco, Pine & More fencing page
- Spare pickets
- None: add your own share for warped or split boards; our sources print no figure
Planner setting or your selection; no external document cited.
How each count is reached
- 9 ft pressure-treated pine 4x4 posts6 ft above ground + 36 in in the ground; 1 end, 2 gate, 11 line
Sources Master Halco PostMaster wood product book (2018); NIST PS 20-25, American Softwood Lumber Standard (Jan 2025)
- 8 ft pressure-treated pine 2x4 rails3 per section × 12 sections
- 6 ft pine pickets, 5 1/2 in wide95.56 ft ÷ 5 1/2 in = 209 + 9 for the gate
- 50 lb bags of concrete mix21.68 cu ft in 14 10 1/2 in holes, less the posts ÷ 0.375 cu ft per bag
Source QUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- 60 lb bags of all-purpose gravel6 in under each post: 4.21 cu ft ÷ 0.6 cu ft per bag
Sources QUIKRETE how-to: Setting Posts without Mixing; Sakrete All Purpose Gravel data sheet
- Gate hinge and latch setsOne per 4 ft gate
Source Bufftech molded and extruded fence installation guide (2201)
All sources (13)
- Master Halco PostMaster wood product book (2018)
- NIST PS 20-25, American Softwood Lumber Standard (Jan 2025)
- Master Halco, Pine & More fencing page
- QUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- QUIKRETE how-to: Setting Posts without Mixing
- Sakrete All Purpose Gravel data sheet
- Bufftech molded and extruded fence installation guide (2201)
- Sakrete 5000 Plus Concrete Mix data sheet (2023)
- QUIKRETE Fast-Setting Concrete Mix 1004 data sheet (Nov 2025)
- Master Halco PostMaster Traditional installation guide
- QUIKRETE Concrete Calculator, help text
- Active Yards horizontal privacy fence instructions (rev 3.22)
- Fortress A2 aluminum fence instructions
Where sources disagree (3)
How deep to set the posts of a 6 ft fence
- 1/3 of the post's length: 36 in · QUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- 1/3 of the post's length: 36 in · Sakrete 5000 Plus Concrete Mix data sheet (2023)
- 1/2 of the height above ground: 36 in · QUIKRETE Concrete Calculator, help text
- 1/3 to 1/2 of the height above ground: 24 in to 36 in · QUIKRETE how-to: Setting Posts without Mixing
- 24 in line posts, 30 in corner and gate posts · Master Halco PostMaster Traditional installation guide
1/3 of the post's length, which both bag makers print; QUIKRETE's calculator says the same in other words.
Hole diameter for a 4x4 post
- 3 × the post's width: 10 1/2 in · QUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- 3 × the post's width: 10 1/2 in · Sakrete 5000 Plus Concrete Mix data sheet (2023)
- 10 in · Bufftech molded and extruded fence installation guide (2201)
- 8 in · Active Yards horizontal privacy fence instructions (rev 3.22)
- 6 in to 10 in · Master Halco PostMaster Traditional installation guide
10 1/2 in: three times the post, the rule printed on both makers' bags. The fence makers dig smaller holes for their own posts.
Gravel under each post
- 6 in · QUIKRETE how-to: Setting Posts without Mixing
- 3 in to 4 in · Sakrete 5000 Plus Concrete Mix data sheet (2023)
- 3 in · Fortress A2 aluminum fence instructions
6 in, QUIKRETE's, the maker whose depth rule and bags the estimate uses.
14 posts · 36 rails · 218 pickets
See listWhat materials a fence needs: how the list is worked out
The example is one straight run, 100 ft long and 6 ft high, in pressure-treated pine with a single 4 ft gate. Each line of its list below shows the rule behind it, then the arithmetic the planner ran.
The gate goes in first
It hangs at the start of the run between two posts. Bufftech leaves 1 in on the hinge side and 3/4 in on the latch side, so the opening and one post take 4 ft 5 1/4 in from post centre to post centre.
Source Bufftech molded and extruded fence installation guide (2201)
Then the sections
The other 95 ft 6 3/4 in is cut at 8 ft on centre, the shortest 2x4 rail on Master Halco's list, so each rail spans one section uncut. That gives 12 sections, the last one 7 ft 6 3/4 in.
Corners and several runs
Corner posts are shared by two runs, so a corner is one post, not two. An L of 50 ft and 50 ft at 8 ft spacing takes 15 posts, where two separate 50 ft runs take 16. Each run is cut into sections on its own and keeps its own short last section. Master Halco sets corner and gate posts 30 in deep and line posts 24 in.
Arithmetic 6 ft above ground + 36 in in the ground; 1 corner, 2 end, 12 line = 15 posts
Source Master Halco PostMaster Traditional installation guide
Posts
A post is buried a third of its whole length, half of what stands above ground: the rule on the QUIKRETE 1101 and Sakrete 5000 Plus sheets. A 6 ft fence puts 36 in in the ground and needs 9 ft posts. For other heights and fence kinds see how deep to set fence posts.
Arithmetic 6 ft above ground + 36 in in the ground; 1 end, 2 gate, 11 line = 14 posts
Sources QUIKRETE Concrete Mix 1101 data sheet (Oct 2022); Sakrete 5000 Plus Concrete Mix data sheet (2023); Master Halco PostMaster wood product book (2018); NIST PS 20-25, American Softwood Lumber Standard (Jan 2025)
Rails
3 rails a section is our own default above 4 ft, since none of the wood-fence makers in our sources prints a count. The real size of the 2x4 rail is on 2x4 actual size.
Arithmetic 3 per section × 12 sections = 36 rails
Pickets
Master Halco's pine pickets are 5 1/2 in wide. Butted together they cover the fenced length and the gate's face, each cut to stop 2 in above the ground. Gaps and board-on-board overlap are counted by the fence picket calculator.
Arithmetic 95.56 ft ÷ 5 1/2 in = 209 + 9 for the gate = 218 pickets
Sources Master Halco PostMaster Traditional installation guide; Master Halco, Pine & More fencing page
Concrete
Each hole is three times the post's width, 10 1/2 in, as both bag makers print, and as deep as the post is buried; the post's own volume comes out. A 50 lb bag of QUIKRETE mix yields 0.375 cu ft. For one post at a time see how many bags of concrete per fence post. For an 80 lb bag and its yield, see how many cubic feet in a bag of concrete.
Arithmetic 21.68 cu ft in 14 10 1/2 in holes, less the posts ÷ 0.375 cu ft per bag = 58 bags
Sources QUIKRETE Concrete Mix 1101 data sheet (Oct 2022); Sakrete 5000 Plus Concrete Mix data sheet (2023)
Gravel
QUIKRETE's how-to sets each post on 6 in of gravel for drainage. A 60 lb bag of Sakrete All Purpose Gravel fills 0.6 cu ft.
Arithmetic 6 in under each post: 4.21 cu ft ÷ 0.6 cu ft per bag = 8 bags
Sources QUIKRETE how-to: Setting Posts without Mixing; Sakrete All Purpose Gravel data sheet
Where fence sources disagree
Bag makers and fence makers print different post depths and hole sizes for the same 4x4. The planner lists every value and digs to the bag makers’ rule, so the concrete count matches the bag it is poured from.
How deep to set the posts of a 6 ft fence
- 1/3 of the post's length: 36 inQUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- 1/3 of the post's length: 36 inSakrete 5000 Plus Concrete Mix data sheet (2023)
- 1/2 of the height above ground: 36 inQUIKRETE Concrete Calculator, help text
- 1/3 to 1/2 of the height above ground: 24 in to 36 inQUIKRETE how-to: Setting Posts without Mixing
- 24 in line posts, 30 in corner and gate postsMaster Halco PostMaster Traditional installation guide
1/3 of the post's length, which both bag makers print; QUIKRETE's calculator says the same in other words.
Hole diameter for a 4x4 post
- 3 × the post's width: 10 1/2 inQUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- 3 × the post's width: 10 1/2 inSakrete 5000 Plus Concrete Mix data sheet (2023)
- 10 inBufftech molded and extruded fence installation guide (2201)
- 8 inActive Yards horizontal privacy fence instructions (rev 3.22)
- 6 in to 10 inMaster Halco PostMaster Traditional installation guide
10 1/2 in: three times the post, the rule printed on both makers' bags. The fence makers dig smaller holes for their own posts.
Gravel under each post
- 6 inQUIKRETE how-to: Setting Posts without Mixing
- 3 in to 4 inSakrete 5000 Plus Concrete Mix data sheet (2023)
- 3 inFortress A2 aluminum fence instructions
6 in, QUIKRETE's, the maker whose depth rule and bags the estimate uses.
| Calculator | Posts | Rails | Pickets |
|---|---|---|---|
| This planner | 14 | 36 | 218 |
| DIYCalcs | 14 | 39 | 230 |
| CalcShed | 15 | 39 | 210 |
| Jobsite Calcs | 16 | 36 | 220 |
Before you dig post holes
A post hole is where a fence can hit a buried line or break a local rule, so settle these first.
Call 811
The call is free and the utilities mark their lines. Colorado asks for 2 days of notice, not counting the day you call. Georgia wants 3 days, Massachusetts 3 business days.
Sources Common Ground Alliance, 811 in Colorado; Common Ground Alliance, 811 in Georgia; Common Ground Alliance, 811 in Massachusetts
Check the frost line
Denver's building code puts its frost line at 36 in, the depth of this example's posts. Massachusetts asks 48 in. Bufftech sets vinyl posts 30 in deep or below the frost line, and Barrette takes its SlideLock posts 6 in past it. Enter your frost depth in the options and the plan warns when the posts stop short.
Sources 2025 Denver Building Code, section 1809.5; 780 CMR 51.00, Massachusetts Residential Code, 10th ed., Table R301.2(1); Bufftech molded and extruded fence installation guide (2201); Barrette SlideLock vinyl fence instructions
Which wood for posts
Choose a pressure-treated post labeled Ground Contact, including when setting it in concrete, or a naturally durable species with mostly heartwood. The Forest Products Laboratory advises pressure-treated lumber, or heartwood of a naturally durable species. A species name alone does not tell you how much durable heartwood is in a post; check the actual piece and its label. The Forest Products Laboratory rates heartwood this way: black locust is very resistant; western redcedar, eastern redcedar, white oak and old-growth redwood are resistant; Douglas-fir is moderately resistant; spruces, hemlocks and pines not named in its table are slightly or nonresistant. Sapwood is not covered by these ratings. Arxada, a maker of treated lumber, lists posts holding up fences, in the ground or in concrete, under Ground Contact. Its guide prints Use Category 4A and 0.15 lb/ft³ of CA-C preservative for sawn fence posts; for pickets it prints 3A, 3B and 0.06. Buy posts rated for ground contact, not above-ground lumber.
Sources USDA Forest Products Laboratory, Wood Handbook (FPL-GTR-282, 2021); Arxada, Wolmanized Outdoor: Above Ground vs Ground Contact applications sheet (2022); Arxada, Wolmanized Outdoor specification guide for treated wood end uses (WOW-5085-R11, 2022)
Ask about a permit
Height usually decides it. Denver wants a zoning permit for any fence over 4 ft. New York City needs none up to 6 ft at one- and two-family homes and caps a front-yard fence at 4 ft. Chicago skips the building permit up to 5 ft where zoning allows the fence.
Sources City and County of Denver, Fences and Walls; NYC Department of Buildings, Fences & Backyard Sheds; Chicago Department of Buildings, work without a permit: fences
Fence calculator questions
How many posts does a 100 ft fence need?
14 posts at 8 ft spacing with one 4 ft gate: 1 end, 2 gate, 11 line. Without the gate the run still takes 14 posts, because the gate's two posts stand where two section posts would.
How deep should the posts of a 6 ft fence go?
36 in, a third of a 9 ft post, by the rule QUIKRETE and Sakrete both print. Master Halco digs its own fences 24 in for line posts and 30 in for end and gate posts, which brings the example to 41 bags. For other heights see how deep to set fence posts.
How many bags of concrete does each fence post take?
About 4.1 bags of 50 lb: the example's 14 posts take 58 bags in 10 1/2 in holes 36 in deep, post subtracted. In 80 lb bags the same holes take 37; each bag's yield is on how many cubic feet in a bag of concrete.
How many pickets does a 100 ft privacy fence take?
218 pickets of 5 1/2 in pine butted together, 9 of them for the gate. Leave a 1/2 in gap between pickets and the count drops to 201 pickets. Set the gap and the overlap in the fence picket calculator.
Should fence posts be 6 ft or 8 ft apart?
At 8 ft every 2x4 rail spans a section without a cut. Closer posts make a stiffer fence and a longer list; for the example: Post spacing 8 ft → 6 ft: +4 posts, +12 rails, +17 bags of concrete, +2 bags of gravel. That is 18 posts in all.
How many posts does a fence with corners need?
A 40 × 60 ft rectangle takes 26 posts at 8 ft spacing, 4 of them corners, and 27 posts with a 4 ft gate in the middle of a 60 ft side. Pick Rectangle, L-shape or U-shape in the size box and enter each side; the plan counts a corner once and draws the shape to scale.
Why do fence calculators give different post counts?
They place the gate differently. For this same 100 ft fence with one gate, DIYCalcs gives 14 posts with no gate field, CalcShed 15 and Jobsite Calcs 16; this planner counts 14, two of them gate posts.
How many fence panels do I need for 100 ft of fence?
12 panels for 100 ft of fence 6 ft high: 11 go in whole at 8 ft between posts, and the last is cut down to 7 ft 6 3/4 in. The 4 ft gate hangs in its own opening, so it takes no panel.