Miscellaneous Concrete Calculators
Written by Shakeel Alvi · Technically reviewed by Muhammad Qasim, PEC Reg. No. 63430 · Last reviewed: 2026-07-11
Four calculators sit in this category because four projects didn't fit anywhere else on the site — a curb, a fence post, a driveway base of recycled rubble, a single deck post. What they share isn't geometry. It's scale: small pours, usually poured by one person in an afternoon.
Curb & Gutter Concrete Calculator
Calculate concrete volume for curb and gutter in yd³, ft³, and m³ with a gutter pan and curb body breakdown. Barrier, rollover, and mountable presets with AASHTO GDPS-4-M compliance check.
Post Hole Concrete Calculator
Estimate concrete, gravel, and bag counts for fence posts, gate posts, deck posts, and more.
Crushed Concrete Estimator Calculator
Calculate crushed concrete volume, tons, coverage, and total cost with compaction adjustments.
Fence Post Concrete Calculator
Calculate concrete bags and volume for fence posts by total fence length and post spacing, with post displacement subtraction and IRC depth check.
What you're deciding in this category
The first split is whether you're filling a void or shaping a form. Post holes and fence posts fill a round or square excavation around a piece of lumber or steel, so the real volume is the hole minus the post, not the hole alone — skip that subtraction and you'll order concrete for a post that isn't there. Curb and gutter work the opposite way: it's a continuous formed shape run for a set linear distance, closer to a beam than a hole. Crushed concrete isn't concrete you're pouring at all — it's aggregate you're buying by the ton to spread and compact as a driveway or path base, and its density swings more than virgin gravel because the source material (broken slab, old curb, demolished walls) varies batch to batch. The second decision, for anything going in the ground, is depth. A post that looks solid at 18 inches can still heave out of the ground every winter if the local frost line sits deeper than that.
Which calculator fits which job
Two of the four calculators handle posts and look similar enough to swap by accident; the other two don't overlap with anything else on the site.
- Curb & Gutter Concrete Calculator
- Use this for a continuous formed curb or gutter run — barrier, rollover, or mountable profile — where the output is a linear volume per foot times total run length, not a single footprint like the other three tools in this category.
- Post Hole Concrete Calculator
- Use this for any single post — deck, mailbox, gate, sign — where you need the hole volume minus the post displacement for one or a handful of holes with independent depths and diameters.
- Crushed Concrete Estimator Calculator
- Use this when you're buying recycled aggregate by the ton for a driveway or path sub-base rather than pouring anything — it converts a footprint and compaction depth into tons and total delivered cost, the same job the gravel hub does for virgin stone.
- Fence Post Concrete Calculator
- Use this instead of the generic post-hole tool once you're setting more than a couple of posts at a fixed spacing along a fence line — it works from total fence length and post interval rather than one hole at a time, and still subtracts post displacement per hole.
Standards that govern Miscellaneous Concrete
AASHTO GDPS-4-M — Sets the curb and gutter cross-section families — barrier, mountable, rollover — the curb calculator's presets are built around; picking the wrong profile changes the gutter-pan-to-curb-body volume split even when the overall footprint looks the same on paper.
IRC R403.1.4 — Sets the minimum footing depth for anything bearing on soil, posts included, tied to the local frost line rather than a fixed national number — a post set to a neighboring state's frost depth can heave in a colder county even if the concrete itself is mixed and cured correctly.
Ordering the hole volume, not the post-and-hole volume
Every calculator in this category that deals with a post subtracts the post's own volume from the hole it sits in — a 4×4 wood post or a 2-inch steel pipe genuinely displaces concrete, and on a small hole that displacement isn't trivial. Skip that step and manually estimate a hole as pure cylinder or pure rectangular prism, and you'll over-order by 10 to 20% on a typical residential post, more on anything using a large timber or pipe. The other trap runs the opposite direction: augers don't cut a clean, rated-diameter cylinder in real soil. Loose or rocky ground lets the hole wander wider than the bit, so actual consumption on multiple holes often runs ahead of the math even after the post subtraction is done correctly.
Frequently Asked Questions
- Do I need to subtract the post from the hole volume?
- Yes — every post calculator on this site subtracts the post's cross-section from the hole, because the post genuinely displaces concrete. A 4x4 post in a 10-inch hole removes a meaningful share of the volume, and skipping that step over-orders material.
- How deep should a fence post go?
- Local frost depth sets the floor, and IRC guidance generally puts it at one-third to one-half of the post's above-ground height, whichever ends up deeper. Check your county's frost line before finalizing depth.
- Is crushed concrete as strong as gravel for a driveway base?
- For compaction purposes, yes, once it's properly graded — but density varies more between loads than virgin gravel does, since the source material differs batch to batch. Confirm gradation with the supplier rather than assuming a fixed number.
- What's the difference between the post-hole and fence-post calculators?
- The post-hole tool prices one hole at a time with independent inputs; the fence-post tool works from total fence length and a fixed post spacing to price an entire run of holes in one pass.
- Do curb and gutter use the same concrete mix as a driveway?
- Usually a similar structural mix, but curb and gutter forms are shaped to a specific cross-section profile — barrier, mountable, or rollover — so the volume math runs per linear foot rather than per square foot.