Concrete Pour Calculator
Estimate concrete by cubic yard, bag count (60 lb + 80 lb), and total material + labor cost for slabs, footings, driveways, sidewalks, and pads.
4–6 in for typical slab on grade
Typical: $140–220/yd³ in most US markets
Placing + finishing. 2.5 hr/yd³ is a solid default.
5% covers over-dig + settlement. Bump for complex shapes.
Result
- Volume
- 33.33 ft³ · 1.23 yd³
- Yards to order (delivered)Rounded up to next quarter-yard
- 1.50 yd³
- 80 lb bags neededIf buying bags instead of delivery
- 59
- Material cost (delivered)
- $270
- Labor cost
- $170
- Total (material + labor)
- $440
This estimate is based on national average costs and may vary by region, project specifics, and market conditions. Use as a starting point for your bids.
How to estimate concrete
Volume is the easy part: length × width × depth (in feet) ÷ 27 gives you cubic yards. Where contractors lose money is on the edges — coming up short on yardage mid-pour, paying short-load fees on partial truck deliveries, or buying bags when delivery would have been cheaper.
This calculator gives you the yards to order (rounded up to the next quarter-yard, which is how concrete is dispatched), bag counts for both 60 lb and 80 lb options, and a labor estimate based on your blended hourly rate. The pour-type picker also surfaces the standard depth range so you can sanity-check the dimensions before you order.
Standard depths by pour type
| Pour | Depth | Notes |
|---|---|---|
| Slab on grade | 4–6 in | 4 in is standard residential. 6 in for garage / shop floors. |
| Footing | 8–12 in | Below grade. Check your local code for soil type + load. |
| Driveway | 4–6 in | 4 in for cars. 6 in if RV / truck traffic. |
| Sidewalk | 3–4 in | 3 in is light foot traffic only. Default 4 in. |
| Equipment pad | 4–6 in | HVAC / AC condenser / generator base. |
| Post hole / pier | Below frost line | 24 in in southern climates. 42+ in northern. |
Bags vs truck delivery
The crossover point is roughly 1 cubic yard (27 ft³). Below that, bagged concrete from the home center is faster than waiting for a truck and you avoid short-load fees ($60–150 in most markets). Above 1 yd³, the math flips hard — bag prices don't scale and mixing by hand consumes labor that evaporates margin.
Two practical thresholds:
- Under 0.5 yd³: bags every time. Most contractors don't even price the truck option.
- 0.5–1 yd³: judgment call. If you have a tow-behind mixer and the site is far from a ready-mix plant, bags still win. Otherwise truck.
- Over 1 yd³: truck delivery. Bags are too slow and the cure window starts working against you.
Pricing your concrete pour
Delivered concrete typically runs $140–220 per cubic yard in most US markets, with regional swings. Add labor (placing, finishing, edging, control joints) at roughly 2–3 hours per cubic yard for a small crew. Don't forget setup costs that don't scale with volume — forms, rebar, vapor barrier, jointing — those eat margin on small pours unless you have a minimum job charge.
A 10 ft × 10 ft × 4 in slab is about 1.25 yd³. At $180/yd³ delivered ($225) plus 3 hours of labor at $55/hr ($165), the raw material+labor is $390. Add forms ($40), rebar/mesh ($60), cure compound ($25), and your overhead, and a fair price to the customer is closer to $900–1,200 depending on access and finish. The calculator above handles the variable math — your fixed costs and margin get layered on top.
Frequently asked questions
How do I calculate cubic yards of concrete?
Multiply length × width × depth (all in feet) to get cubic feet, then divide by 27. A 10 ft × 10 ft slab at 4 in deep is 10 × 10 × 0.333 = 33.3 ft³ ÷ 27 = 1.23 yd³. Always order to the next quarter-yard up — concrete is rejected fast if you come short mid-pour.
How thick should a concrete slab be?
4 in is standard for residential slab-on-grade (sheds, patios, sidewalks). Bump to 6 in for vehicle traffic. Footings run 8–12 in. Equipment pads (HVAC, AC condenser) are 4–6 in. Post holes go below frost line, which varies by region — anywhere from 24 in in the south to 42+ in up north.
60 lb bags vs 80 lb bags — which is more economical?
80 lb bags yield about 0.60 ft³ each and run roughly $5–6 retail. 60 lb bags yield about 0.45 ft³ each at $4–5. The 80 lb bag is cheaper per cubic foot in raw material, but the 60 lb is more manageable for solo work. For anything over half a yard (~13 ft³), delivered concrete usually beats bags on both price and time.
When should I switch from bags to truck delivery?
Most contractors switch around 1 yd³ (27 ft³). Below that, bags are faster than coordinating a truck. Above that, mixing by hand becomes labor-intensive and the cure window matters. Truck delivery in most markets has a 1–2 yd³ minimum plus a short-load fee for anything under the full truck (~9 yd³).
What's a normal waste factor for concrete?
5% is the industry default. It covers slight over-dig of the formwork, settlement, and the inevitable shortage at the last corner. Increase to 7–10% if your form work isn't tight, the subgrade is uneven, or you're pouring complex shapes (curves, deep footings).
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