Concrete Calculator (2026) – Cubic Yards, Bags & Cost
Calculate cubic yards, cubic feet, bag counts, and ready-mix cost for slabs, footings, columns, sonotubes, and steps — with a 10% waste factor built in. Updated for 2026 US pricing.
Specialized Concrete Calculators
Concrete Slab Calculator
Slabs, patios, driveways, garage floors. Cost by region + rebar estimator.
Concrete Bag Calculator
40, 60, 80 & 90 lb bags. Quikrete, Sakrete & store-brand comparison.
Concrete Yardage Calculator
Cubic yards for ready-mix orders. Truck load sizing + short-load fees.
Concrete Footing Calculator
Strip footings, pad footings, round footings, and fence post holes.
For driveways, patios, garage floors, sidewalks, and any flat rectangular pour.
For continuous footings, foundation walls, and retaining walls.
For round columns, sonotubes (concrete tube forms), and fence/deck post holes.
For front entry steps, porch steps, and exterior concrete stairs.
Results
Adjust inputs and click Calculate
*Bags recommended for <1 yd³ projects. Use ready-mix for larger pours. Prices vary by supplier and region.
How to Calculate Concrete — The Formula
Concrete volume is always calculated in cubic feet first, then converted to cubic yards (divide by 27) for ready-mix orders, or kept in cubic feet for bag calculations.
Slab Formula (Rectangular)
Cubic Feet = Length (ft) × Width (ft) × Thickness (ft)
Cubic Yards = Cubic Feet ÷ 27
Example: 10 ft × 10 ft × (4 in ÷ 12) = 10 × 10 × 0.333 = 33.3 ft³ = 1.23 yd³
Round Column / Sonotube Formula
Cubic Feet = π × (Diameter ÷ 2)² × Height
Example: 10-inch diameter × 24-inch depth:
= 3.1416 × (0.417 ft)² × 2 ft = 1.09 ft³ per hole
Steps Formula
Each step volume = Width × Riser Height × Cumulative Depth
Total = sum of all steps (pyramid method)
3 steps at 4 ft wide, 7-in rise, 12-in tread ≈ 1.17 ft³
Bags vs. Ready-Mix — Which Should You Use?
The decision between bagged concrete and ready-mix depends almost entirely on project volume. The crossover point is roughly 0.75–1.0 cubic yards.
| Factor | Bagged Concrete | Ready-Mix (Truck) |
|---|---|---|
| Best project size | Under 0.75 yd³ (20 ft³) | Over 1 yd³ |
| Cost per yd³ | $200–$350 (80 lb bags) | $150–$200 |
| Setup | Mixer or by hand, any time | Must be ready when truck arrives |
| Minimum order | As little as 1 bag | Usually 1 full truck (8–10 yd³) |
| Short-load fee | None | $15–$25/yd³ under minimum |
| Labor | High — mixing is physical | Low — truck mixes and pours |
| Quality consistency | Variable — depends on mixing | Consistent — plant-batched |
| Recommended for | Post holes, small pads, repairs | Driveways, slabs, foundations |
2026 Concrete Cost Guide
Concrete costs vary significantly by US region, PSI mix strength, and whether you're buying bags or ready-mix. Here are 2026 benchmarks:
Ready-Mix Cost by US Region
| US Region | Price per Cubic Yard | Key States |
|---|---|---|
| Northeast | $175 – $225/yd³ | NY, NJ, CT, MA, PA |
| West Coast | $165 – $215/yd³ | CA, WA, OR |
| Midwest | $140 – $175/yd³ | IL, OH, MI, MN, IN |
| South | $130 – $165/yd³ | TX, FL, GA, NC, TN |
| Mountain West | $150 – $190/yd³ | CO, AZ, NV, UT |
Bag Concrete Cost (2026)
| Bag Size | Yield (ft³) | Avg. Price | Cost per yd³ |
|---|---|---|---|
| 40 lb bag | 0.30 ft³ | $5.50 – $7.00 | ~$280 – $350 |
| 50 lb bag | 0.375 ft³ | $6.50 – $8.50 | ~$260 – $340 |
| 60 lb bag | 0.45 ft³ | $7.00 – $9.50 | ~$230 – $310 |
| 80 lb bag | 0.60 ft³ | $9.00 – $12.00 | ~$210 – $280 |
| 90 lb bag | 0.675 ft³ | $10.00 – $13.50 | ~$200 – $270 |
Source: aggregated Home Depot, Lowe's, and regional supplier pricing, 2026. Prices vary by location and fluctuate with cement commodity prices.
Concrete Mix Ratios & PSI Guide
Not all concrete is the same. The PSI (pounds per square inch) rating tells you the compressive strength — the higher the PSI, the stronger and more expensive the mix. Use the right PSI for your project type.
| Application | Recommended PSI | Standard Mix Ratio | Notes |
|---|---|---|---|
| Sidewalks, patios | 2,500 – 3,000 PSI | 1:2:3 | Standard residential flatwork |
| Driveways | 3,000 – 3,500 PSI | 1:1.5:3 | Needs to handle vehicle weight |
| Garage floors | 3,500 – 4,000 PSI | 1:1.5:3 | Consider fiber mesh reinforcement |
| Foundations / footings | 3,500 – 4,500 PSI | 1:1:2 | Check local code requirements |
| Structural columns | 4,000 – 5,000 PSI | 1:1:2 | Usually requires engineer spec |
| Pool decks | 4,000 PSI | 1:1.5:3 | Add air-entraining admixture |
| Commercial / industrial | 5,000+ PSI | Engineered mix | Requires structural engineering |
Mix ratios are expressed as cement : sand : aggregate by volume. Higher cement ratios = higher PSI but also higher cost and more shrinkage cracking risk. For most residential work, a bagged mix labeled "General Purpose" or "3000 PSI" is appropriate.
Concrete Thickness by Project Type
Thickness is the most impactful variable in how much concrete you need. A 6-inch slab uses 50% more concrete than a 4-inch slab of the same area. Always verify local building code requirements — some jurisdictions have minimum thickness mandates.
| Project | Recommended Thickness | Notes |
|---|---|---|
| Sidewalks | 4 inches | ACI minimum for exterior flatwork |
| Patio / backyard slab | 4 inches | Increase to 6 in for heavy outdoor furniture |
| Residential driveway | 4 – 6 inches | 6 in recommended for SUVs and trucks |
| Garage floor | 4 – 6 inches | Thicken to 6 in around perimeter/edges |
| Pool deck | 4 – 5 inches | Non-slip finish required |
| Commercial driveway | 6 – 8 inches | For delivery trucks, 8 in minimum |
| Residential foundation | 8 – 12 inches | Verify with local building code |
| Heavy equipment pad | 8 – 12 inches | Requires structural engineering for >10 tons |