How Many Bags of Concrete for 10 Fence Posts?
Ten posts is a common project size — long enough that guessing gets expensive, short enough that a quick calculation covers the whole shopping trip in one go. The total depends on post size, hole size, and depth, same as any single post, just multiplied out.
Quick answer
Ten standard 4×4 posts, in 10-inch holes 24 inches deep, need about 20 bags of 80 lb concrete (or 30 bags of 50 lb). Ten larger 6×6 posts in wider 16-inch holes need closer to 60 bags of 80 lb. If any of your 10 are gate or corner posts, add those separately — they typically use a wider hole than the rest.
For your exact post size and hole dimensions, the Fence Post Concrete Calculator gives you the total instantly.
Totals for 10 posts, by size
| Post & hole | Depth | Bags per post | Total for 10 |
|---|---|---|---|
| 4×4, 8 in hole | 18 in | 1 | 10 |
| 4×4, 10 in hole | 24 in | 2 | 20 |
| 4×4, 12 in hole (gate/corner) | 30 in | 4 | 40 |
| 6×6, 12 in hole | 30 in | 3 | 30 |
| 6×6, 16 in hole (gate/corner) | 30 in | 6 | 60 |
Before you buy 20 (or 60) bags, check these two things
At 10 posts, the total starts to matter beyond just the math. Twenty 80 lb bags weighs 1,600 pounds — worth confirming your vehicle can actually carry that in one trip, or planning on two. It’s also close to the point where a pallet discount kicks in at many suppliers, so it’s worth asking about bulk pricing before checking out bag by bag.
If some of your 10 are gate or corner posts
Don’t apply one number to all 10 if the project isn’t actually uniform. Calculate line posts and gate/corner posts separately, then add the two totals together.
Example: 8 standard 4×4 line posts (2 bags each = 16 bags) + 2 corner posts in a wider hole (4 bags each = 8 bags) = 24 bags total, not the 20 you’d get from treating all 10 the same.
What to confirm before you calculate
- Post size4×4 or 6×6, using actual dimensions.
- How many of the 10 are gate or corner postsThese typically need a separate, larger calculation.
- Hole diameter and depthConsistent across the standard posts, wider for gate/corner.
- Bag sizeAffects both total bag count and total weight to transport.
Worked examples
Example 1 — 10 identical 4×4 posts, standard fence line
- Per-post total (10 in hole, 24 in deep)2 bags
- 10 posts10 × 2 = 20 bags
Example 2 — 10 identical 6×6 posts, solid privacy fence
- Per-post total (16 in hole, 30 in deep)6 bags
- 10 posts10 × 6 = 60 bags
Example 3 — 8 line posts + 2 corner posts, 4×4
- 8 line posts (2 bags each)16 bags
- 2 corner posts (4 bags each)8 bags
- Total24 bags
Get your exact total.
Enter your post size, hole dimensions, and post count for an instant bag count.
Use the free Fence Post Concrete CalculatorComparing bag sizes for the same 10 posts
Same project (4×4, 10 in hole, 24 in deep), shown across every common bag size:
| Bag size | Total bags for 10 posts | Total weight |
|---|---|---|
| 40 lb | 40 | 1,600 lb |
| 50 lb | 30 | 1,500 lb |
| 60 lb | 30 | 1,800 lb |
| 80 lb | 20 | 1,600 lb |
| 90 lb | 20 | 1,800 lb |
80 lb comes out ahead on total bag count without adding extra total weight compared to the alternatives — generally the most practical choice unless you’re working entirely solo and want lighter individual bags to lift.
Mistakes specific to multi-post orders
- Applying one bag count to every post regardless of typeGate and corner posts need their own, larger calculation.
- Not checking total weight before loading a vehicleTwenty 80 lb bags is 1,600 lb — worth confirming your vehicle’s payload capacity.
- Skipping the pallet pricing questionBulk orders in this range often qualify for a discount that isn’t automatically applied.
- Buying exactly the calculated total with no waste allowanceThe same 10% rule applies whether it’s 1 post or 10.
- Not accounting for a post or two being replaced laterA couple of spare bags, stored dry, covers a future repair without a special trip.
Quick reference: totals for common 10-post projects
| Project | 80 lb bags | Approx. weight |
|---|---|---|
| 10 metal T-posts, light garden fence | 5-10 | 400-800 lb |
| 10 standard 4×4 posts, 6 ft fence | 20 | 1,600 lb |
| 8 line + 2 corner (4×4) | 24 | 1,920 lb |
| 10 standard 6×6 posts, 6 ft privacy fence | 60 | 4,800 lb |
What changes the total most
- Post size6×6 posts roughly triple the total compared to 4×4 at similar hole proportions.
- How many are gate or corner postsEach one adds meaningfully more than a standard line post.
- DepthSet by fence height and local frost line — a bigger factor than most people expect.
- Bag size chosenChanges total bag count and total weight, though not proportionally.
Calculate your 10-post total in five steps
- Confirm post size and hole dimensions for your standard line posts.
- Calculate the per-post bag count using the standard formula.
- Multiply by however many are standard line posts.
- Calculate gate/corner posts separately and add that total.
- Check total weight and ask about pallet pricing before you buy.
Frequently asked questions
How many bags of concrete do I need for 10 fence posts?
About 20 bags of 80 lb concrete for 10 standard 4×4 posts in 10-inch holes, 24 inches deep. Larger 6×6 posts need closer to 60 bags for the same count.
Do gate posts count the same as line posts in this total?
No. Gate and corner posts typically use a wider hole and need a separate, larger calculation — don’t apply the line-post number to all 10 if some are gate or corner posts.
How much does 20 bags of concrete weigh?
Twenty 80 lb bags weighs 1,600 pounds — worth checking against your vehicle’s payload capacity before loading it all in one trip.
Is it worth asking about a discount for 10 posts’ worth of bags?
Often, yes. This quantity frequently crosses into pallet or bulk pricing territory at many suppliers — it’s usually not applied automatically, so ask directly.
Which bag size is most efficient for 10 posts?
80 lb bags typically need the fewest total bags without adding extra total weight compared to smaller sizes — a practical default unless you specifically want lighter individual bags.
Should I buy a few extra bags beyond the calculated total?
A couple of spare bags is reasonable, both as a waste buffer and to cover a future post replacement without a special trip — just store them dry.
Does this math change for 6×6 posts instead of 4×4?
Yes, significantly — 6×6 posts use a wider hole and displace more volume, roughly tripling the total compared to 4×4 posts at similar proportions.
What if my 10 posts are a mix of sizes?
Calculate each size group separately using its own hole dimensions, then add all the totals together for the full project count.
Related reading
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