Concrete Pad Cost Calculator

A professionally installed concrete pad typically runs $600 to $2,500 depending on size and use, even though the concrete material itself is cheap. A small AC or trash-bin pad is often $600–$900, a generator or pool-pump pad $800–$1,200, a hot tub pad $1,500–$2,500, and a shed foundation $1,200–$2,000. The key thing to understand: pads are small, so the price is driven by the contractor's job minimum and the 'short-load' fee for delivering less than a full concrete truck, not by square footage. A 4×4 pad and a 4×8 pad often cost nearly the same because both hit the minimum. The drivers are the pad size, the usage type (which sets the thickness and reinforcement), site prep, and access. Enter your dimensions and pad usage in the calculator to anchor the estimate.

Because the fixed costs of any concrete job — mobilizing a crew, forming, ordering and delivering concrete, and finishing — don't shrink much for a small pad, so they spread over very few square feet. A ready-mix truck charges a 'short-load' fee for delivering under a full load (about 10 yards), and a contractor has a minimum project charge (commonly $600–$1,000) to make a small job worth the trip. So a 16 sq ft AC pad and a 32 sq ft pad can cost almost the same, both landing near the minimum. This is why combining pads — pouring the AC pad, generator pad, and a walkway in one visit, or adding the pad to a larger concrete job — is far more cost-effective per square foot: you pay the fixed costs once. The calculator reflects this with a job minimum, so very small pads show the minimum rather than a tiny per-foot total.

It depends on the load. A standard 4-inch pad handles light items — AC units, heat pumps, trash bins, and small sheds. A 6-inch reinforced pad is recommended for heavy or vibrating equipment: hot tubs (water weighs about 8.3 lbs per gallon, so a full tub is thousands of pounds), large standby generators, and pool equipment. The calculator's usage type sets the thickness and rate automatically — a hot tub pad is priced for a thicker, reinforced pour, a generator pad for heavier-duty concrete, and general/AC/trash pads for standard thickness. Going too thin under a heavy load invites cracking and settling; over-building a tiny AC pad wastes money. Matching thickness to the actual load is the point of the usage selection. For anything carrying significant weight or vibration, add reinforcement and don't skimp on the base.

No — pouring straight onto dirt is a classic mistake that leads to settling, shifting, and cracking. You first need to remove the topsoil and organic matter (which decomposes and creates voids), then install and compact a gravel base, typically 3–4 inches of crushed stone. The gravel base does two crucial jobs: it provides a stable, uniform bearing surface so the pad doesn't settle unevenly, and it drains water away from under the slab so freeze-thaw and moisture don't undermine it. On clay or poorly draining soils, the base is even more important. The calculator includes a gravel-base-prep add-on (+$3/sq ft) for exactly this. Skipping the base to save a little money is the single most common reason a pad cracks or tips within a few years — it's not the place to cut corners.

Wait at least 7 days before placing equipment — concrete reaches about 70% of its strength in a week, which is enough for most lighter items. For very heavy loads like a hot tub full of water, waiting the full 28 days (when concrete reaches its design strength) is safest, since loading a green slab too early can crack it. You can usually walk on a fresh pad within a day or two, but bearing weight is different from foot traffic. Cold weather slows curing, so add time if you poured below about 50°F. Your installer will tell you the safe wait for your specific pad and load. Planning the pour ahead of when you actually need the equipment in place — ordering the hot tub or generator to arrive after the cure window — avoids the temptation to load it too soon.

Yes — for heavy or vibrating equipment, reinforcement is well worth it. Generators vibrate substantially while running, and that cyclic stress will crack plain concrete over time; rebar or heavy-gauge wire mesh holds the slab together and resists vibration cracking. Hot tubs impose a large, concentrated, sustained load that benefits from reinforcement and a thicker slab to spread it. For light, static items like a trash-can or small AC pad, mesh or even plain 4-inch concrete on a good base is usually fine. The calculator's usage types price hot tub and generator pads for reinforced, heavier-duty pours, while general/AC/trash pads assume standard concrete. The cost of rebar is trivial next to the cost of replacing a cracked pad — and a cracked pad under a generator or hot tub can also misalign or damage the equipment, so reinforce where the load demands it.

Usually not for a small equipment pad, but it depends on your jurisdiction and what's going on the pad. Most small ground-level pads (AC, generator, trash bins, a small hot tub) don't need a permit, though larger slabs (often over 100–200 sq ft), anything attached to the house, or pads tied to a permitted project (a new generator's electrical, a hot tub's wiring and plumbing) may require one. Even when the pad itself doesn't need a permit, check local zoning for property-line setbacks — equipment and structures often must sit a minimum distance from the lot line — and any HOA rules. A shed on a concrete pad may need a structures permit. When in doubt, a quick call to the building department settles it. The electrical/plumbing hookups for generators and hot tubs frequently need permits even if the pad doesn't, so factor those in.

It depends on the shed and your priorities. A concrete shed pad is permanent, perfectly level, pest- and rot-proof, and lets you anchor the shed firmly — it costs more ($8–$15/sq ft with a job minimum) but is the most durable, low-maintenance base, ideal for heavier sheds, workshops, or anything you'll keep long-term. A gravel pad (a timber-framed box filled with compacted crushed stone) is cheaper ($4–$6/sq ft), drains exceptionally well, and is great for portable or lighter sheds — but it's less stable over time, can shift, and won't anchor a structure as solidly. For a permanent shed or a wood-floored shed where moisture matters, concrete usually wins; for a lighter prefab or metal shed on a budget, gravel is a sensible choice. The calculator estimates the concrete pad option, including anchor bolts and a gravel base if you want both.

For very small pads — like a 3×3 AC pad or a 2×3 pad for a single appliance — mixing bags of pre-mixed concrete (Quikrete or similar) on site is reasonable and avoids the short-load fee. But it adds up fast: an 80-lb bag yields only about 0.6 cubic feet, so it takes roughly 45 bags per cubic yard, and mixing more than a handful by hand is exhausting and hard to keep consistent. For anything larger than about 8×8, ordering ready-mix from a truck gives cleaner, stronger, more uniform concrete that's all placed in one continuous pour (important for strength and avoiding cold joints), and it's usually cheaper per yard once you factor in your labor. The crossover is roughly half a yard: under it, bags make sense; over it, ready-mix is better. The calculator estimates professional ready-mix installation; for a tiny DIY pad you could compare against bag costs.

Combine jobs. Because the cost is dominated by the job minimum and short-load fee, the single biggest saving is to pour everything you need in one visit — the AC pad, the generator pad, a shed slab, and a walkway together, or add the pad to a larger concrete project like a driveway or patio. You pay the mobilization, delivery, and minimum once instead of for each small pad. Beyond that: pick the right size (about 12 inches larger than the equipment on each side, not oversized), choose the appropriate thickness for the load rather than over-building, ensure good truck access so you don't pay wheelbarrow or pump fees, and have the site clear and marked before the crew arrives. Don't skimp on the gravel base, though — that's the one place 'saving' reliably backfires with a cracked pad. The calculator lets you bundle add-ons to model a combined job.