Concrete Calculator
Calculate concrete volume in cubic yards for slabs, footings, columns, walls, and stairs. Includes bag counts (40, 60, 80 lb), waste factor, and cost estimates.
Related Calculators
About This Calculator
Accurate concrete estimation is critical for any construction project—order too little and you'll have an incomplete pour, order too much and you waste money on excess material. Our Concrete Calculator computes the exact cubic yards needed for slabs, footings, columns, walls, stairs, and post holes, then adds an appropriate waste factor for spillage and uneven surfaces.
2026 concrete market: Ready-mix concrete prices have increased 9% year-over-year through early 2025, with current costs averaging $150-$180 per cubic yard for standard 3,000 PSI mix delivered to residential sites. Full truckloads (9-10 yards) offer the best per-yard pricing at $120-$150, while short loads (under 5 yards) incur $50-$100 additional fees, pushing effective costs to $170-$220 per yard.
For DIY projects, bagged concrete from Quikrete or Sakrete costs $4-$6 per 80-lb bag at Home Depot and Lowe's, yielding 0.6 cubic feet per bag. That works out to $270-$400 per cubic yard when mixing yourself—significantly more expensive than ready-mix for projects over 1 yard, but practical for small jobs under 0.5 cubic yards.
The average concrete driveway costs $6-$15 per square foot for plain gray concrete, or $8-$20+ per square foot for stamped or decorative finishes. A typical 2-car driveway (400 sq ft) runs $2,400-$8,600 depending on finish and thickness. Whether you're pouring a patio, setting fence posts, or building a foundation, getting the quantity right is the first step to a successful project.
How to Use the Concrete Calculator
- 1Select your project type (slab, footing, column, wall, stairs, or post hole).
- 2Enter dimensions in feet for length/width/height and inches for thickness/diameter.
- 3For multiple identical items (columns, post holes), specify the quantity.
- 4In advanced mode, adjust the waste factor (5-15% depending on project complexity).
- 5Review cubic yards needed—round UP to the nearest 0.25 yard for ready-mix orders.
- 6Compare costs between ready-mix delivery and bagged concrete for your project size.
- 7For projects over 1 cubic yard, ready-mix is almost always more economical.
Concrete Volume Formulas
Different project types require different calculations:
Slabs and Patios (Rectangular)
Volume (cu ft) = Length (ft) × Width (ft) × Thickness (in) ÷ 12
Cubic Yards = Volume (cu ft) ÷ 27
Example: 10 ft × 12 ft patio, 4 inches thick
- Volume = 10 × 12 × (4/12) = 40 cu ft
- Cubic Yards = 40 ÷ 27 = 1.48 cu yd (order 1.75 with waste)
Footings (Continuous)
Volume = Length (ft) × Width (in)/12 × Depth (in)/12
Round Columns/Sonotubes
Volume = π × (Diameter ÷ 24)² × Height (ft)
= 3.14159 × radius² × height
| Diameter | Per Foot Depth |
|---|---|
| 8" | 0.029 cu yd |
| 10" | 0.045 cu yd |
| 12" | 0.065 cu yd |
| 18" | 0.145 cu yd |
| 24" | 0.259 cu yd |
Walls
Volume = Length (ft) × Height (ft) × Thickness (in) ÷ 12
Stairs (Approximation) Stairs require calculating:
- Treads: Number × Width × Depth × Thickness
- Risers: Number × Width × Height × Thickness
- Fill: Triangular section beneath steps
- Landing: Length × Width × Depth
Post Holes
Volume per hole = π × (Diameter/24)² × Depth (ft)
Total Volume = Volume per hole × Number of holes
2026 Ready-Mix Concrete Pricing
Current ready-mix concrete costs reflect 9% year-over-year price increases:
Pricing by PSI Strength:
| Concrete Type | PSI Rating | Price/Cubic Yard | Best Use |
|---|---|---|---|
| Economy | 2,500 | $120-$140 | Sidewalks, light-use slabs |
| Standard | 3,000 | $130-$160 | Driveways, patios, garages |
| Heavy-duty | 4,000 | $150-$180 | Commercial, heavy traffic |
| High-strength | 5,000+ | $180-$220 | Structural, industrial |
Full Load vs. Short Load:
| Order Size | Base Price | Short Load Fee | Effective Cost/Yard |
|---|---|---|---|
| 9-10 yards (full) | $130-$165/yd | None | $130-$165 |
| 5-8 yards | $140-$175/yd | $25-$50 | $145-$190 |
| 3-4 yards | $150-$185/yd | $50-$75 | $165-$210 |
| 1-2 yards | $160-$200/yd | $75-$100 | $200-$250 |
Additional Fees to Expect:
| Fee Type | Typical Cost | When Applied |
|---|---|---|
| Short load (<5 yards) | $50-$100 | Orders under minimum |
| Saturday/weekend | $30-$75 | Non-business hours |
| After-hours | $50-$100 | Early morning/evening |
| Winter/hot weather | $5-$10/yd | Extreme temperatures |
| Colored concrete | $8-$15/yd | Integral color added |
| Fiber reinforcement | $5-$10/yd | Fiber mesh added |
| Pump truck | $150-$500 | Hard-to-reach areas |
| Standby time | $2-$3/minute | After 5-10 min grace |
Regional Price Variations:
- West Coast (CA, WA, OR): $165-$220/yd (+15-25%)
- Northeast (NY, NJ, MA): $150-$200/yd (+10-15%)
- Midwest (OH, IL, MI): $125-$165/yd (baseline)
- South (TX, FL, GA): $120-$160/yd (-5-10%)
Bagged Concrete: Quikrete vs Sakrete
For small DIY projects, bagged concrete offers convenience without delivery minimums:
2026 Retail Pricing (Home Depot/Lowe's):
| Bag Size | Yield (cu ft) | Price Range | Bags/Cubic Yard |
|---|---|---|---|
| 80 lb | 0.60 | $4.50-$6.00 | 45 bags |
| 60 lb | 0.45 | $3.50-$4.50 | 60 bags |
| 50 lb | 0.38 | $3.00-$4.00 | 72 bags |
| 40 lb | 0.30 | $2.50-$3.50 | 90 bags |
Cost Per Cubic Yard (Materials Only):
| Bag Size | Bags Needed | Cost/Yard |
|---|---|---|
| 80 lb | 45 | $200-$270 |
| 60 lb | 60 | $210-$270 |
| 50 lb | 72 | $215-$290 |
| 40 lb | 90 | $225-$315 |
Pallet Discounts:
- 80 lb bags: 42-45 per pallet, ~$3.50/bag ($150-$160/pallet)
- Full pallets often include free delivery over $500
Quikrete vs Sakrete Comparison:
| Feature | Quikrete | Sakrete |
|---|---|---|
| Standard strength | 4,000 PSI | 4,000 PSI |
| Set time | 24-48 hrs | 24-48 hrs |
| Walk-on time | 24 hrs | 24 hrs |
| Full cure | 28 days | 28 days |
| Availability | Widespread | Regional |
When to Use Bagged Concrete:
- Projects under 0.5 cubic yards (13.5 cu ft)
- Remote locations without truck access
- Multiple small pours over time
- Post holes, small repairs, patches
When Ready-Mix Is Better:
- Projects over 0.5-1 cubic yard
- Single continuous pour required
- Time is valuable (mixing is labor-intensive)
- Consistent quality needed
Concrete Thickness Requirements by Code
Building codes specify minimum thicknesses—these are minimums, not recommendations:
Residential Slab Requirements (IRC/IBC):
| Application | Code Minimum | Recommended | Heavy Duty |
|---|---|---|---|
| Interior floor on grade | 3.5" | 4" | 5" |
| Garage floor | 4" | 4" | 5" |
| Patio | 3.5" | 4" | 4" |
| Sidewalk | 3.5" | 4" | 4" |
| Residential driveway | 4" | 5" | 6" |
| RV/truck driveway | 5" | 6" | 6-8" |
| Foundation slab | 4" | 6" | 6-8" |
Commercial/Heavy Use:
| Application | Minimum | Typical |
|---|---|---|
| Commercial driveway | 6" | 7-8" |
| Parking lot | 5" | 6" |
| Warehouse floor | 5" | 6-8" |
| Loading dock | 6" | 8" |
Subgrade Requirements:
| Component | Specification |
|---|---|
| Vapor barrier | 6-mil polyethylene minimum |
| Barrier overlap | 6" minimum at seams |
| Base material | 4-6" compacted gravel/crusite |
| Compaction | 95% Proctor density |
| Slope for drainage | 1/8" per foot minimum |
Reinforcement by Application:
| Slab Thickness | Minimum Reinforcement |
|---|---|
| 3.5-4" | 6×6 W1.4×W1.4 wire mesh or fiber |
| 4-5" | 6×6 W2.1×W2.1 mesh or #3 rebar 18" OC |
| 5-6" | #3 or #4 rebar at 18" centers |
| 6"+ | #4 rebar at 12-18" per engineer |
PSI Requirements by Use:
| Application | Minimum PSI | Recommended |
|---|---|---|
| Interior slabs | 2,500 | 3,000 |
| Exterior slabs | 3,000 | 3,500 |
| Driveways | 3,000 | 4,000 |
| Freeze-thaw exposure | 3,500 | 4,500 |
| Structural footings | 2,500 | 3,000 |
Project Cost Estimator: Materials + Labor
Complete project costs including labor for common concrete work:
Concrete Driveways (2026):
| Finish Type | Per Sq Ft | 400 Sq Ft (2-car) |
|---|---|---|
| Plain gray | $6-$10 | $2,400-$4,000 |
| Broom finish | $7-$11 | $2,800-$4,400 |
| Exposed aggregate | $10-$15 | $4,000-$6,000 |
| Basic stamped | $12-$18 | $4,800-$7,200 |
| Premium stamped | $15-$25 | $6,000-$10,000 |
| Colored/stained | $8-$14 | $3,200-$5,600 |
Concrete Patios:
| Size | Plain | Stamped/Decorative |
|---|---|---|
| 10×10 (100 sf) | $600-$1,000 | $1,200-$2,500 |
| 12×12 (144 sf) | $850-$1,450 | $1,700-$3,600 |
| 15×15 (225 sf) | $1,350-$2,250 | $2,700-$5,600 |
| 20×20 (400 sf) | $2,400-$4,000 | $4,800-$10,000 |
Garage Floors:
| Size | Plain | Epoxy Coated |
|---|---|---|
| 1-car (200 sf) | $1,200-$2,000 | $2,000-$3,500 |
| 2-car (400 sf) | $2,400-$4,000 | $4,000-$7,000 |
| 3-car (600 sf) | $3,600-$6,000 | $6,000-$10,500 |
Sidewalks (4" thick):
| Width | Per Linear Foot |
|---|---|
| 3 ft | $15-$25 |
| 4 ft | $20-$33 |
| 5 ft | $25-$42 |
Labor Breakdown:
| Task | Cost Range |
|---|---|
| Form work | $1.50-$3/sq ft |
| Concrete pour/finish | $2-$5/sq ft |
| Wire mesh install | $0.50-$1/sq ft |
| Rebar install | $1-$2/sq ft |
| Stamping/decorative | $3-$8/sq ft |
| Old concrete removal | $1-$3/sq ft |
| Gravel base work | $0.50-$1.50/sq ft |
Planning Your Concrete Pour
Successful concrete work requires careful preparation:
Before Ordering Ready-Mix:
- Calculate accurately with 5-10% waste factor
- Confirm truck access:
- 12 feet wide clearance
- 20+ feet overhead clearance
- Weight limit (40,000 lbs loaded)
- Street parking if needed
- Check weather:
- No rain within 24 hours
- Temperature 50-90°F ideal
- No freeze risk for 7 days
- Prepare site:
- Excavation complete
- Forms set and braced
- Subgrade compacted
- Vapor barrier placed
- Rebar/mesh ready
Ordering Checklist:
| Specification | Standard Residential |
|---|---|
| Quantity | Calculated + 5-10% |
| PSI strength | 3,000-4,000 |
| Slump | 4-5 inches |
| Aggregate | 3/4" standard |
| Fiber | Optional |
| Color | If applicable |
Day of Pour Timeline:
| Time | Activity |
|---|---|
| T-1 hour | Wet subgrade lightly (not muddy) |
| T-30 min | Final form check, tool staging |
| Arrival | Direct truck, verify ticket |
| Pour | Continuous, no stopping |
| +15-30 min | Bull float, initial leveling |
| +45-90 min | Edging, jointing, finishing |
| +2-4 hours | Troweling (if smooth finish) |
| +4-8 hours | Apply curing compound or cover |
Minimum Crew Sizes:
| Pour Size | Crew Needed |
|---|---|
| 1-2 yards | 2 people minimum |
| 3-5 yards | 3-4 people |
| 6-10 yards | 4-6 people |
| 10+ yards | 5+ people + finishers |
Working Time by Temperature:
| Temperature | Usable Time |
|---|---|
| 50-60°F | 2+ hours |
| 70-80°F | 90 minutes |
| 80-90°F | 60-75 minutes |
| 90°F+ | 45-60 minutes |
Waste Factors and Ordering Guidelines
Proper waste calculation prevents running short:
Recommended Waste Factors:
| Project Type | Waste Factor | Reason |
|---|---|---|
| Flat slabs, level ground | 5% | Minimal variation |
| Slabs, uneven ground | 10% | Subgrade irregularities |
| Footings in trenches | 10% | Soil cave-ins, irregularities |
| Post holes | 10-15% | Hole shape variation |
| Stairs | 15% | Complex geometry |
| Walls | 5-7% | Form variations |
| Columns | 5% | Predictable shapes |
| Architectural/decorative | 10-15% | Color/finish matching |
Ordering Rules of Thumb:
- Always round UP to nearest 0.25 yard
- Never order exact calculated amount—you WILL run short
- Short load fees often make ordering extra economical
- Leftover concrete can be used for:
- Extra stepping stones
- Equipment cleaning pads
- Post hole caps
- Future patch material (if bagged)
Example Waste Calculation:
Patio: 12 ft × 15 ft × 4" thick
- Volume: 12 × 15 × (4/12) = 60 cu ft
- Cubic yards: 60 ÷ 27 = 2.22 cu yd
- With 7% waste: 2.22 × 1.07 = 2.38 cu yd
- Order: 2.5 cubic yards
What Happens If You Run Short:
- Must stop pour—creates permanent cold joint
- Cold joints crack, leak, and are structurally weak
- May need to demolish and start over
- Extra cost: $500-$2,000+ to fix
What Happens With Extra:
- Dispose of hardened concrete ($50-$150)
- Use for other small projects
- Some plants accept return loads (minus fee)
- Small excess = cheap insurance
Pro Tips
- 💡Always order 5-10% extra concrete—running short mid-pour creates permanent structural problems (cold joints) that may require demolition.
- 💡Verify truck access before ordering: trucks are 30+ feet long, 8+ feet wide, weigh 40,000+ lbs loaded, and need 20 feet overhead clearance.
- 💡Never add water on-site to make concrete more workable—each gallon per yard added reduces strength by 150-200 PSI.
- 💡Request a 4-5 inch slump for most residential work—higher slump is easier to work but weaker and more prone to cracking.
- 💡Cure concrete properly by keeping it moist for 7 days minimum—use curing compound, plastic sheeting, or regular water spraying.
- 💡For projects over 1 cubic yard, ready-mix is almost always cheaper than bagged—compare total costs including your time.
- 💡Check weather carefully: no rain for 24 hours, temperatures 50-90°F, no freeze risk for 7 days after pour.
- 💡Have adequate help—minimum 2 people per cubic yard, with bull floats, edgers, and trowels staged and ready.
- 💡Install control joints every 8-10 feet (max 2-3× the slab thickness) to control where cracks occur—they're inevitable.
- 💡Use fiber reinforcement or wire mesh in all slabs—rebar in driveways and heavy-traffic areas at 18-inch centers.
- 💡For colored concrete, order 10-15% extra to ensure consistent color throughout—partial orders may vary.
- 💡Consider pump truck rental ($150-$500) if truck access is difficult—much faster than wheelbarrowing and reduces labor.
Frequently Asked Questions
A 10×10 foot slab at 4 inches thick requires 1.23 cubic yards (33.3 cubic feet). That equals approximately 56 bags of 80-lb concrete, 74 bags of 60-lb, or 111 bags of 40-lb. Add 5-10% for waste (3-6 extra 80-lb bags). For a project this size (over 1 cubic yard), ready-mix delivery at $180-$250 is typically more economical than $250-$340 in bags, plus you avoid mixing labor.
