Slabs • Patios • Driveways • Footings • Posts
Use this Concrete Calculator in Maryland to estimate cubic feet, cubic yards, concrete bags and material cost for Maryland-area slabs, patios, driveways, sidewalks, footings, posts and other concrete projects. Enter your actual dimensions and local material price for a project-specific estimate.
Estimate slabs and patios, continuous footings, round posts/columns, or convert known square footage into bags and ready-mix cost.
Enter finished dimensions for a patio, driveway panel, garage slab, sidewalk section or other rectangular concrete flatwork.
Verify manufacturer bag yield.
Thickened edges, footings, steps and other deeper concrete sections should be calculated separately.
Estimate a uniform continuous footing, grade beam or strip foundation.
Estimate concrete for cylindrical posts, piers and round columns.
Already know the square footage? Convert area and slab thickness into cubic yards, bag quantity and material cost.
The calculator works from geometry, so the first step is measuring the actual concrete dimensions. For a slab, patio or driveway panel, measure finished length and width and enter the planned slab thickness. For a footing, measure total continuous length and use the actual width and depth from the project design. For posts or piers, use the finished diameter and poured height/depth.
After calculating exact volume, compare it with an optional allowance. The allowance is not a mandatory Maryland percentage—it simply gives you a larger planning quantity to compare against the mathematical volume.
Use finished concrete dimensions.
Slab, footing, round post or area.
Use the project-specific concrete thickness.
Enter an Maryland-area supplier quote if desired.
Check permits, plans and field dimensions.
For most rectangular slabs, the concrete quantity formula is straightforward.
Cubic yards = cubic feet ÷ 27.
A 20 × 20 foot slab at 4 inches thick contains about 133.33 cubic feet, or approximately 4.94 cubic yards before an ordering allowance.
| Project | Example Size | Thickness | Approx. Concrete |
|---|---|---|---|
| Small Patio | 10 × 12 ft | 4 in | 1.48 yd³ |
| Patio / Slab | 12 × 20 ft | 4 in | 2.96 yd³ |
| Garage Floor | 20 × 20 ft | 4 in | 4.94 yd³ |
| Driveway Section | 20 × 30 ft | 5 in | 9.26 yd³ |
| Large Slab | 30 × 40 ft | 6 in | 22.22 yd³ |
These are geometric examples only. Actual thickness, reinforcement, base preparation and project design can differ.
Location-focused guidance without forcing a single local price.
Calculations use project dimensions rather than broad averages.
Compare bagged concrete for smaller pours.
Estimate cubic yards before requesting a supplier quote.
Slabs are among the most common concrete projects in Central Maryland, including patios, garage floors, sheds, equipment pads and other flatwork. The slab calculator converts the surface footprint and thickness into concrete volume.
Do not use excavation depth as slab thickness. Excavation can also contain compacted base, drainage layers or other materials. Enter the actual concrete thickness shown on the project plan.
For a dedicated slab page, use the Concrete Slab Calculator. For floor-specific work, use the Concrete Floor Calculator.
For a rectangular patio, multiply length by width to get square footage, then multiply by slab thickness. Irregular patios can be divided into rectangles, circles or other simple shapes and calculated separately.
Use the Concrete Patio Calculator for circular and L-shaped patio geometry.
A driveway estimate should be based on the actual driveway footprint and the specified thickness. If different driveway sections have different thicknesses, calculate each section separately and add the cubic-yard quantities.
Permit, right-of-way and driveway-access requirements can vary by city, county and road authority. Check the local building or engineering department for the property before construction. For statewide building-code information, use the Maryland Department of Commerce Building Codes page.
Continuous strip footings and grade beams are calculated from total length × width × depth. The calculator does not size a footing structurally. Soil conditions, loads, building type and code requirements can affect foundation design, so use dimensions from approved plans or qualified design guidance.
For more detail, use the Concrete Footing Calculator or Concrete Foundation Wall Calculator.
Round concrete posts and piers use the cylinder formula π × radius² × height. If the project includes an enlarged footing at the bottom, calculate that footing separately. For larger structural columns, use the Concrete Column Calculator.
Concrete prices can change by supplier, mix specification, delivery distance, order size and additional service charges. Rather than hard-coding a citywide price, the calculator lets you enter a current local quote per cubic yard.
For sealer quantities after the project is ready for treatment, use the Concrete Sealer Coverage Calculator.
This Concrete Calculator in Maryland can be used for quantity estimates in Baltimore, Columbia, Germantown, Silver Spring, Frederick, Rockville, Gaithersburg, Bowie, Annapolis, Hagerstown and communities across the state. Use it for slabs, patios, garage floors, sidewalks, driveway sections, footings, foundation elements, posts and other common concrete shapes.
The volume formulas do not change by county: measure finished concrete dimensions, enter the actual thickness and calculate cubic yards. Ready-mix prices, minimum-load fees, delivery zones, permits and local amendments can vary, so enter your own supplier price rather than relying on a statewide average.
For sidewalks, driveway slabs and private walkways, calculate area from length × width and multiply by the specified concrete thickness. If a driveway connects to a public road, right-of-way work, driveway entrances, curb work or drainage can be subject to additional county, municipal or highway-agency requirements.
Use this calculator for material quantity, then verify the exact permit and construction requirements with the local jurisdiction. For State Highway Administration work, use current MDOT SHA specifications and project details.
Maryland concrete projects can face both hot-weather and seasonal-weather placement conditions. Summer heat, humidity, sun and wind can accelerate moisture loss, while winter temperatures can slow setting and early strength development. Weather does not change the geometric cubic-yard calculation, but it can change batching, delivery, placement, finishing, protection and curing procedures.
For cold conditions, review ACI 306R-16: Guide to Cold Weather Concreting. For hot-weather work, the ACI PRC-305-20: Guide to Hot Weather Concreting is a useful technical reference.
For curing schedule planning after placement, use the Concrete Cure Time Calculator.
Exterior concrete in Maryland should be planned around drainage, subgrade support and seasonal temperature changes. Western and northern parts of the state can experience more severe winter exposure, while coastal and central areas can also see repeated freezing and thawing. The calculator estimates material volume only; it does not design frost protection, air entrainment, base thickness, reinforcement, joints or drainage.
Before ordering ready-mix, verify excavation, compacted base, forms, reinforcement and access. Uneven subgrade or unplanned deeper areas can increase the quantity even when nominal slab dimensions have not changed.
Maryland's Building Performance Standards establish statewide minimum building-code requirements, but local counties and municipalities administer and enforce building codes and can adopt certain local modifications. Permit requirements therefore depend on the project location and scope.
For the current statewide code framework, use the official Maryland Department of Labor Building Codes Administration page. For an actual slab, driveway, footing, foundation or structural project, also contact the county or municipal building official for permit, zoning, right-of-way and inspection requirements.
Maryland's official Building Codes Administration identifies the Maryland Building Performance Standards (MBPS) as the statewide framework based on the International Building Code, International Residential Code and International Energy Conservation Code with State modifications. Local jurisdictions may make certain modifications and should be contacted for current local requirements.
As of the Maryland Department of Labor's March 18, 2026 adopted-code matrix, the current MBPS building, residential and energy code editions are the 2021 IBC, 2021 IRC and 2021 IECC. Maryland began a 2026 rulemaking process to adopt the 2024 editions, with proposed changes published June 26, 2026. Because that update process is ongoing, check the current official State and local pages before relying on a specific edition.
This Concrete Calculator in Maryland is a quantity estimator only. It does not determine structural slab thickness, footing depth, frost protection, reinforcement or code compliance.
Small repairs and pads may be practical with bagged concrete, while larger slabs, patios and footings can require many bags. The calculator lets you compare approximate bag quantity with ready-mix cubic yards.
Bag yields vary by manufacturer and product. Verify the package yield before purchasing. For larger pours, ready-mix can simplify batching but may include delivery minimums, short-load fees or waiting-time charges.
The exact mathematical quantity assumes uniform thickness, perfect forms and zero placement loss. Real job sites can differ because of uneven base elevations, over-excavation, form tolerance or concrete left in placement equipment.
The calculator's allowance field is optional. Choose the final order based on actual field conditions and supplier guidance.
Concrete is volume, so thickness must be included.
The calculator expects slab thickness in inches and converts it automatically.
Calculate each thickness zone separately.
Add deeper concrete geometry separately.
Enter a current supplier quote instead of relying on an old citywide average.
Check official Maryland permitting information for the exact project scope.
The calculator does not select slab thickness, footing size, reinforcement or concrete strength.
Concrete sidewalks, curbs, gutters, entrances, drainage structures, barriers and roadway work under public contracts should follow the applicable agency plans and specifications rather than generic residential assumptions.
For Maryland State Highway Administration work, use the current MDOT SHA Construction and Material Standards and Specifications and the project contract documents. The agency also publishes its Book of Standards for highway and incidental structures.
The same cubic-yard formulas apply throughout Maryland, but project details can vary between Baltimore City, Baltimore County, Montgomery County, Prince George's County, Anne Arundel County, Howard County, Frederick County and other jurisdictions. Local amendments, inspections, driveway-entrance rules and right-of-way requirements should be checked before construction.
Use this page for quantity planning, then confirm the mix specification, delivery schedule, permit requirements and construction details with the appropriate project professionals and suppliers.
Concrete quantity comes from finished project dimensions. Weather affects placement and curing procedures, not the basic geometric volume.
Suppose a Maryland residential slab is 12 feet by 20 feet and 4 inches thick. The area is 240 square feet, and the thickness is one-third of a foot.
With a 10% planning allowance, the calculator shows about 3.26 cubic yards.
Common questions about Maryland concrete yards, slabs, patios, driveways, bags, cost and permits.