Calculate cubic yards, bags needed, and Kansas City-accurate ready-mix costs for any project — driveways, patios, foundations, garage slabs, footings & more across Missouri and Kansas.
Enter your project dimensions to calculate volume, bags needed, and estimated Kansas City material cost.
Residential driveway: 4–5 in., 3,500 PSI with 5–6% air entrainment. KC's freeze-thaw winters demand air entrainment. Expansive clay soil — compact and crown properly. 36-in frost depth for footings per KC MO & KS code.
Driveway 4–5 in · Garage 4–5 in · Patio 4 in · Foundation 6 in · Footings 36+ in deep
Kansas City is one of America's largest metro areas straddling two states — Missouri (Jackson, Clay, and Platte Counties) and Kansas (Wyandotte and Johnson Counties) — with a combined metro population exceeding 2.2 million. The city is a major Midwest construction hub with both residential growth in the suburbs (Overland Park, Lenexa, Lee's Summit, Liberty) and significant urban redevelopment downtown. Concrete in KC is defined by two key environmental challenges: a continental climate with cold winters requiring air-entrained concrete for all exterior flatwork, and among the most problematic expansive clay and loess soils in the central United States. The metro's geology — primarily Missouri River and Kansas River alluvial and floodplain deposits overlaying thick Pennsylvanian shale and limestone bedrock — creates soil conditions that move dramatically with seasonal moisture changes. A dry Kansas City summer followed by a wet spring can cause unrestrained native clay to shrink and swell by 2–4 inches, making proper subgrade preparation and drainage the most critical factors in long-term KC concrete performance.
All Exterior Exposed Concrete (driveways, patios, sidewalks): 3,500 PSI minimum; 5–6% air entrainment required for KC freeze-thaw winters; w/c ratio ≤ 0.45 · Garage Floors: 3,500 PSI, 4–5 in. thick; vapor barrier required over KC clay soils; seal after 28-day cure · Foundation Slabs: 3,500 PSI minimum, 6 in. thick; expansive clay subgrade must be pre-wetted, compacted, and stabilized or replaced with select fill before placement · Footings: 36-inch minimum frost depth per Kansas City MO Code of Ordinances Chapter 18 and Kansas City KS Unified Government Code Section 8-412 — both mandate 36 inches · Cold-Weather Pours: Do not pour when ground or air temperature is below 40°F without heated enclosures and insulating blankets · Always confirm requirements with the KC MO Development Services or KC KS Unified Government Permits for your specific project side of the state line.
A standard 20×20 ft KC driveway at 4 inches requires ~5.4 cubic yards of 3,500 PSI air-entrained concrete with a 10% waste factor. Kansas City's freeze-thaw winters mean air entrainment is essential — without it, driveway surfaces typically begin scaling within 3–6 winters. The more unique KC challenge is the expansive clay subgrade: many KC driveways that crack and heave are not victims of poor concrete but of inadequately prepared native clay underneath. A proper KC driveway requires removing the top 4–6 inches of native clay, compacting a 4–6 inch crushed limestone base, and crowning the slab ¼ inch per foot for drainage away from the home. Installed driveways run $9–$14/sq ft in the current KC market — comparable to other major Midwest metros.
A two-car garage (20×22 ft) at 4–5 inches needs ~5.4–6.7 cubic yards of 3,500 PSI concrete. Kansas City garage floors face the same expansive clay challenge as driveways — the native clay under a garage slab can move enough to crack an unrestrained 4-inch slab within 5–10 years if the subgrade is not properly stabilized. A vapor barrier is mandatory over KC clay soils, and a compacted crushed rock base of at least 4 inches is strongly recommended before slab placement. Polypropylene fiber or #4 rebar on 24-inch centers provides practical crack control over expansive soils. Apply a penetrating sealer or epoxy coating after 28-day cure to protect the surface from the road salts tracked in by vehicles during Kansas City winters. Garage floor pours run $10–$16/sq ft installed in the KC metro.
Foundation design in the Kansas City metro is significantly influenced by the area's expansive Pennsylvanian-age clays and Missouri River loess deposits. These soils are highly moisture-sensitive — they shrink significantly in KC's dry summers and swell in the spring rains, generating enough pressure to crack or lift lightly loaded foundation slabs. The standard KC residential foundation response is either a full basement (common in Missouri portions of the metro) — which places the foundation below the active clay zone — or a post-tensioned slab-on-grade engineered to resist differential movement. Any significant foundation project in KC should include a geotechnical investigation and soil bearing test, particularly in areas with known fill, near the Missouri or Kansas River floodplains, or on slopes where moisture migration is unpredictable. Footings must extend to 36 inches per code in both KC MO and KC KS.
Measure your project's length and width in feet and thickness in inches. Multiply length × width × (thickness ÷ 12) to get cubic feet, then divide by 27 for cubic yards. Add a 10% waste factor for standard KC projects — KC's clay subgrade surfaces can be uneven after stripping, adding unexpected volume variation, and being short means a second load with a short-load fee of $130–$290 per delivery ticket from KC suppliers. For large KC commercial or foundation projects, always confirm the subgrade is properly prepared, compacted to 95% standard Proctor, and has passed a soil bearing test before pouring.
Kansas City concrete projects face two primary hazards unique to its Mid-America geology and climate. (1) Expansive clay movement: KC's native Pennsylvanian clay soils are among the most expansive in the Midwest. Placing concrete directly on unprepared native clay — without removing the top layer, pre-wetting to equilibrium moisture content, and compacting a granular base — is the leading cause of cracked, heaved, and failed flatwork in the KC metro. Never skip the 4–6 inch crushed limestone base on any KC concrete flatwork. On foundation projects, native clay must either be removed and replaced with select fill, lime-stabilized in place, or bypassed entirely via a properly engineered post-tensioned slab or deep foundation system. (2) Freeze-thaw and air entrainment: Kansas City averages 20+ freeze-thaw cycles per winter. Non-air-entrained exterior concrete will begin to scale and spall within 3–6 winters in KC. Always specify 3,500 PSI with 5–6% air entrainment for every KC driveway, patio, sidewalk, and exposed flatwork project — and never add water to the mix on site to ease placement, as this destroys both strength and the air void system.
The table below reflects typical volumes and current Kansas City metro ready-mix pricing of $145–$175/yd. Installed costs include forming, standard labor, broom finish, and control joints — excluding excavation, crushed rock base, permits, vapor barriers, and clay subgrade treatment. Pricing is consistent across both the Missouri and Kansas sides of the metro. Always collect at least three bids from licensed KC concrete contractors before committing.
| Project Type | Typical Size | Thickness | Cu Yards | Material Cost | Installed Estimate | Notes |
|---|---|---|---|---|---|---|
| Driveway (Standard) | 20 × 20 ft | 4 in. | ~5.4 yd | $837 | $1,900 – $3,200 | 3,500 PSI + 5% Air |
| Garage Floor (2-car) | 20 × 22 ft | 5 in. | ~6.7 yd | $1,039 | $2,400 – $3,900 | 3,500 PSI + Vapor |
| Patio / Backyard Slab | 16 × 20 ft | 4 in. | ~4.7 yd | $729 | $1,500 – $2,600 | 3,500 PSI + 5% Air |
| Foundation Slab | 1,500 sq ft | 6 in. | ~18.5 yd | $2,868 | $9,000 – $16,000 | Clay Prep Critical |
| Sidewalk / Walkway | 4 × 40 ft | 4 in. | ~2.0 yd | $310 | $800 – $1,400 | 3,500 PSI + 5% Air |
| Commercial / Industrial | 40 × 60 ft | 6 in. | ~44.4 yd | $6,882 | $18,000 – $33,000 | 4,000–5,000 PSI |
The Kansas City metro sits within the Dissected Till Plains physiographic region, underlain by Pennsylvanian-age shale, limestone, and coal measures topped by deep glacial till and alluvial deposits from the Missouri and Kansas Rivers. The top 5–20 feet of soil throughout much of the metro consists of highly plastic, expansive smectite clays and wind-deposited loess — two of the most challenging soil types for concrete flatwork in North America. Kansas City soils are classified by USDA as primarily Sharpsburg, Grundy, and Lagonda series — all characterized by high plasticity index (PI 25–45), high liquid limit, and significant shrink-swell potential. In the Missouri River bottomlands and Kansas River floodplain — including much of downtown KC, the West Bottoms, and lower Argentine — soils may also include younger alluvial deposits, artificial fill from historic levee construction, and areas of known liquefaction susceptibility in a seismic event.
The most effective strategies for concrete over Kansas City's expansive clays are: (1) Remove and replace — strip the top 6–8 inches of native clay and replace with compacted crushed limestone or gravel, which provides a stable, non-expansive working platform. (2) Pre-wet to equilibrium — if you cannot remove the clay, wet the subgrade to its natural field moisture content 48–72 hours before the pour and compact to 95% standard Proctor. This prevents the post-pour drying-shrinkage crack that opens under a newly placed slab. (3) Lime stabilization — mixing 3–5% agricultural or quicklime into the top 6–8 inches of native KC clay reduces plasticity and virtually eliminates shrink-swell for foundation and heavy flatwork projects. Used extensively by KC commercial contractors, this is worth considering for any residential foundation or large driveway over native clay. (4) Post-tensioned slab design — for residential foundations in KC, post-tensioning is the engineering-preferred solution that accommodates differential clay movement without cracking the slab.
Confirm permit requirements and clay subgrade guidance before any KC pour.
Kansas City Missouri's Development Services manages building permits, plan review, and inspections for residential and commercial concrete projects on the Missouri side of the metro. They can advise on current frost depth requirements, expansive soil provisions under the adopted building code, floodplain overlay requirements near the Missouri River, and permit fees for your specific project type. The KC MO Building Code is available online at kcmo.gov — always confirm locally adopted amendments before finalizing any foundation or structural concrete design.
Visit KCMO.govThe Unified Government of Wyandotte County/Kansas City, Kansas manages building permits and code enforcement for the Kansas side of the KC metro. Their adopted building code mandates the 36-inch frost depth applicable to all KCK footings and foundations. Kansas City KS's industrial corridors and older urban neighborhoods may have fill soils and brownfield conditions that require special geotechnical investigation before foundation or structural concrete work. Verify contractor licensing through the Kansas Contractor Licensing Board before any permitted project.
Visit WycoKCK.orgGeiger Ready-Mix has served the Kansas City area for over 70 years and is one of the region's most established ready-mix concrete suppliers. Their online concrete calculator is specifically calibrated for KC-area projects and can help you estimate yardage before calling for a quote. Geiger supplies both residential and commercial mixes across the KC metro from multiple plant locations. Call (913) 281-0111 to request a current quote — always compare at least three KC suppliers before committing to a ready-mix order for any project over 5 yards.
Geiger Ready-Mix KC