Concrete Pad Cost Calculator
Estimate installed cost for an AC unit, shed, or hot tub pad — concrete material plus finishing labor, excluding base prep and permits.
How this calculator works
This estimates the installed cost of a small concrete pad — material (cubic yards from the standard slab-volume formula, times your price per cubic yard) plus finishing labor (your pad’s area times a per-square-foot labor rate). Both price fields are editable placeholders; use a local contractor quote for a precise number.
Formula: Cubic yards = (Length ft × Width ft × Depth ft) ÷ 27. Total cost = (Cubic yards × Price/yd³) + (Area sq ft × Labor rate/sq ft).
Worked example
A 10 ft × 10 ft (100 sq ft) pad at 4 inches, $150/yd³ material, $6/sq ft labor:
- Depth in feet: 4 ÷ 12 = 0.3333 ft
- Cubic yards: (10 × 10 × 0.3333) ÷ 27 ≈ 1.2346 → 1.23 yd³
- Material cost: 1.2346 × $150 ≈ $185.19
- Labor cost: 100 × $6 = $600.00
- Total estimated cost: $785.19
Cost reference (at default rates)
| Pad size | Estimated total cost |
|---|---|
| 5 ft × 5 ft | ~$196 |
| 10 ft × 10 ft | ~$785 |
| 20 ft × 20 ft | ~$3,141 |
How to measure your area
Measure the finished footprint you need, not just the equipment’s base — add 3-6 inches of clearance around AC units, generators, or sheds so the pad extends slightly past the structure’s edges. For hot tubs, use the manufacturer’s specified pad dimensions rather than the tub’s outer shell size.
Frequently asked questions
What does this pad cost estimate include and exclude?
It includes concrete material (cubic yards × price per yard) and finishing labor (area × labor rate). It excludes gravel base prep, forms, rebar or wire mesh, and any permit fees — small pads like AC and generator slabs often don't need permits, but sheds and hot tub pads sometimes do, so check locally.
What size pad do I need for a typical AC unit or generator?
Most residential AC condensers and standby generators sit on a 3 ft × 3 ft to 4 ft × 4 ft pad, well under this calculator's 10 ft × 10 ft default. Enter your unit's footprint plus a few inches of clearance on each side.
Should a hot tub pad be thicker than 4 inches?
Often yes. A filled hot tub can weigh 3,000-5,000+ lbs, so many manufacturers and installers recommend 4-6 inches of reinforced concrete rather than the standard 4-inch unreinforced slab this calculator defaults to. Adjust the depth field and add rebar cost separately.
Why is the labor rate the same regardless of pad size?
The $6/sq ft default is a per-square-foot average for forming, pouring, and finishing a small flatwork slab. Very small pads (under ~25 sq ft) sometimes cost more per square foot in practice because setup and forming time doesn't shrink proportionally with the pour — treat the estimate as a floor for tiny pads.
How is this different from the Concrete Pad Calculator?
The Concrete Pad Calculator gives you cubic yards only. This page adds an installed labor cost on top, so you get a full budget number instead of just a materials quantity.
Estimates only. Verify quantities with your supplier before purchasing.