Garden Fence Calculator
Fencing for a garden perimeter
🔒 No server · Method · · Disclaimer · Garden Fence Calculator
Working out fencing for a garden perimeter is easier with Garden Fence Calculator, which answers as you type. You supply Length (ft), Width (ft) and Height (ft) to Garden Fence; the answer follows at once. The answer from Garden Fence arrives with its working attached. Garden Fence shines when speed matters. Nothing is uploaded while Garden Fence works, and the figures stay put. Garden Fence sits in the Home & Garden section next to free online garden fence calculator and garden fence calculator perimeter posts roll. Garden Fence shows formula, assumptions and result together. Try Garden Fence now and keep it handy.
What the defaults give
A 20 × 15 ft garden has a 70 ft perimeter and needs 10 posts at 8 ft spacing.
The fence area is 280 sq ft, which comes to about 12 rolls of 25 sq ft mesh.
The formula
Perimeter = 2 × (length + width)
Posts = ceil(perimeter ÷ post spacing) + 1
Mesh area = perimeter × height
Rolls = ceil(mesh area ÷ roll coverage)
The plus one closes the loop: a 16 foot run with posts every 8 feet needs posts at 0, 8 and 16 feet, which is three, not two. The ceiling rounds up the last partial bay, so 70 ÷ 8 = 8.75 becomes 9 bays and 10 posts.
Worked examples
20 × 15 ft, 8 ft spacing → 70 ft perimeter, 10 posts, 12 rolls
20 × 15 ft at 6 ft spacing → ceil(11.67) + 1 = 13 posts
20 × 15 ft at 10 ft spacing → ceil(7) + 1 = 8 posts
30 × 20 ft at 8 ft → 100 ft, 14 posts, 16 rolls at 4 ft high
10 × 10 ft at 8 ft → 40 ft, 6 posts
20 × 15 ft with 3 ft mesh → 210 sq ft, 9 rolls
Post spacing in practice
Eight feet is the common compromise for a garden fence: close enough that wire mesh does not sag between posts, far enough that you are not buying timber every few steps. Six feet is better for a fence that will take a gate, a climbing plant or a dog leaning on it; ten feet is fine for a light mesh barrier around a bed but will bow under a stretched roll.
Corners count as posts, and a gate needs two posts of its own plus a sturdy hinge post — usually a heavier section set deeper. If your plot is not a true rectangle, walk the actual boundary and add the segments, because a diagonal or a curve has more perimeter than the bounding box suggests.
Depth and materials the count leaves out
Each post needs a hole about a third of its above-ground height deep, so a 4 ft fence with 4 ft posts should be set 18 to 24 inches down, in concrete for anything holding tension. That is 10 bags of postcrete at the defaults, which is often the largest single line on the receipt after the mesh.
Add fixings, tension wire, staples, a top rail if the mesh is light, and 5% spare mesh for cuts and mistakes. The roll figure assumes full rolls are used with no waste, so buy 5% to 10% above the calculated area, and check the actual coverage printed on the roll — nominal 25 sq ft rolls vary between manufacturers.
Frequently Asked Questions
How many posts for a 20 by 15 foot garden?
10 at 8 foot spacing. The perimeter is 70 feet, which is 9 bays rounded up, plus one post to close the run.
How much mesh for that fence?
About 12 rolls of 25 sq ft mesh for a 4 ft fence, because 70 ft times 4 ft is 280 sq ft. Buy 5% to 10% extra for cuts.
What post spacing should I use?
Eight feet for light garden mesh, six feet if a gate, climbing plant or animal will load it, and ten feet only for a very light barrier.
Do corners count as posts?
Yes, and a gate needs two additional posts plus a heavier hinge post set deeper. Walk the real boundary rather than the bounding rectangle.
How deep should the posts go?
About a third of the above-ground height: 18 to 24 inches for a 4 ft fence, set in concrete if the mesh will be under tension.
Plant Spacing & Quantity Calculator and other Home & Garden tools
Plant Spacing & Quantity Calculator · Pool Chemical Balance Calculator · Tile Grout & Mortar Calculator · Solar Battery / Home Battery Calculator · Deck Post Spacing · Firewood Calculator · Home & Garden Guides