Estimate Concrete for San Francisco Slabs, Driveways, Patios & Footings
Use this Concrete Calculator in San Francisco to estimate cubic yards, cubic feet, ready-mix volume, bags and optional material cost for concrete projects in San Francisco. Calculate rectangular slabs, patios and driveways, continuous footings, round pads and piers, or convert a known volume into bags and truck-load planning.
Calculate slabs and driveways, continuous footings, round pads/piers, or convert known concrete volume into bags and ready-mix planning quantities.
Estimate concrete for a rectangular slab using length, width, thickness and allowance.
Quantity estimate only. Slab thickness, reinforcement, base preparation, joints, drainage and concrete specification must match the actual San Francisco project requirements.
Estimate rectangular footing or grade-beam concrete from continuous length, width and depth.
Estimate cylindrical concrete volume from diameter, depth/thickness and quantity.
Start with known concrete volume and estimate bags, ready-mix truck equivalents and optional cost.
Verify the exact bag's published yield
Start by choosing the geometry that matches the concrete you plan to place. A patio, driveway section or slab is usually calculated as a rectangular prism. A continuous footing or grade beam is calculated from length, width and depth. A round pier or pad uses the cylinder formula. If a contractor or supplier already gave you a volume, use the bags and ready-mix mode to convert that volume into ordering quantities.
The calculator first determines exact geometric volume. It then applies the selected planning allowance. The allowance is not a structural design factor; it simply helps account for uneven grade, form variation, small spills and the fact that actual field dimensions rarely match perfect geometry.
Use the average concrete thickness actually intended for the placement.
Calculate stepped or varying footing sections separately when dimensions change.
Diameter and depth are converted from inches to feet before calculating cubic yards.
Estimate concrete volume for rectangular driveway sections and extensions.
Calculate backyard patios, shed slabs, equipment pads and general flatwork.
Estimate continuous concrete for additions, walls and foundation elements.
Convert adjusted cubic yards into editable truck-equivalent and cost estimates.
For most residential flatwork, the key inputs are length, width and average thickness. A 20 ft × 12 ft slab contains 240 square feet. At 4 inches thick, the exact volume is 80 cubic feet or about 2.96 cubic yards. With a 10% planning allowance, the calculator shows approximately 3.26 cubic yards.
That same formula can be used for a San Francisco patio, walkway section, concrete pad or a rectangular driveway panel. If the project has several areas with different thicknesses, calculate each area separately and add the adjusted results rather than forcing one average thickness across the entire job.
Driveways often contain multiple geometric sections: the main parking area, a narrower approach, flared corners or an extension beside an existing driveway. Divide the layout into rectangles, calculate each one and add the cubic yards. This produces a more reliable takeoff than multiplying the longest overall length by the widest overall width.
Do not let an online material calculator choose driveway thickness or reinforcement for you. Those details depend on vehicle loading, subgrade, base, drainage, joints, existing conditions, project design and any local requirements that apply to the work.
A backyard patio is usually straightforward to measure, but small dimensional errors can still change the order. Measure the formed dimensions after layout when possible. If the patio has a step, thickened edge, footing for a cover or isolated equipment pad, calculate those volumes separately.
For decorative concrete, stamped concrete or exposed-aggregate work, the volume formula stays the same. Decorative finish does not reduce the quantity of base concrete required.
The footing mode converts continuous length, width and depth into cubic yards. For example, 100 linear feet of footing that is 18 inches wide and 12 inches deep contains 150 cubic feet, or about 5.56 cubic yards before allowance.
Actual foundation dimensions should come from the approved project documents where required. Do not use a calculator to choose footing width, depth, reinforcement or bearing requirements.
Round piers are calculated as cylinders. A 24-inch-diameter pier has a radius of 1 foot. If it is 36 inches deep, one pier contains π × 1² × 3 = about 9.42 cubic feet, or roughly 0.35 cubic yard before allowance. Multiple identical piers are multiplied by the entered quantity.
This mode can also be used for round equipment pads, sign bases or other cylindrical concrete elements when the geometry is reasonably uniform.
Perfect geometric volume assumes perfectly shaped excavation, perfectly straight forms and no material loss. Real placements can differ. Many estimators add a modest project allowance and then coordinate the final order with the ready-mix supplier.
This calculator provides 0%, 5%, 10%, 15% and 20% options. The appropriate amount depends on the certainty of the dimensions, excavation quality, project size and ordering increments. A large arbitrary allowance is not automatically better because excess ready-mix can create disposal and cost problems.
Bagged concrete can be practical for small repairs, isolated posts, tiny pads or projects where a ready-mix truck cannot access the placement. Bag yield varies by product and bag size, so the calculator keeps yield per bag editable.
Ready-mix is usually easier to plan for larger placements. The usable truck capacity field is editable because truck payload and supplier policies can differ.
Concrete permit requirements in San Francisco depend on the scope, location and structural role of the work. The Department of Building Inspection is responsible for inspecting new and existing buildings and structures for conformity with approved plans and permits and for compliance with state and local building code requirements. Structural slabs, foundations, additions, retaining elements and other building-related concrete can therefore require approved construction documents and inspections.
A small private flatwork project can follow a different path from a structural foundation or work that touches the sidewalk, street or other public right-of-way. Before ordering concrete, verify the current permit path for the actual property and project rather than assuming that every patio, driveway or slab is handled the same way.
The 2025 California Building Standards Code, Title 24 became effective January 1, 2026. The California Building Standards Commission states that this edition is effective through December 31, 2028. San Francisco applies state building standards together with local code provisions and permit requirements.
Concrete design involves much more than cubic-yard quantity. Structural slabs, foundations, retaining elements and building additions can require specific concrete strength, reinforcement, cover, detailing, seismic design, footing geometry and inspections. Use the approved plans and applicable current code for those requirements. This Concrete Calculator in San Francisco estimates material volume only.
San Francisco construction can involve steep lots, variable grades and seismic site considerations. PermitSF reforms signed in 2025 changed portions of the City's slope and seismic hazard review framework, but they did not make a quantity calculator suitable for geotechnical or structural design. The state building code continues to provide processes for evaluating construction on slopes where applicable.
For concrete takeoff, measure the actual approved geometry. For structural design, use the geotechnical, survey, structural and permit documents required for the project. Do not use a generic footing depth, slab thickness or retaining-wall dimension simply because it produces a convenient cubic-yard quantity.
San Francisco Public Works' Bureau of Street Use and Mapping permits and inspects use of the public right-of-way, including sidewalks and streets. Public Works reviews permits, plans and specifications for street, sidewalk, excavation and repair work and checks compliance with applicable codes, regulations, permit conditions, accessibility requirements and approved grades.
If a driveway crossing, sidewalk repair, curb area, excavation or pavement restoration lies in the public right-of-way, calculate that concrete separately from the private slab. Public-side work can have distinct permit, accessibility, grade, traffic-control, restoration and inspection requirements.
Concrete quantity should be based on the finished form and excavation geometry. Low spots increase concrete volume; high spots can reduce thickness. Proper base and drainage design also matter for performance, especially around driveways, patios and areas adjacent to buildings.
Measure after forms are set when possible. If the subgrade varies significantly, use field measurements or break the project into sections. Avoid assuming that every point beneath a slab is exactly the same depth.
Private driveway concrete and the portion that crosses or interfaces with a public sidewalk should be measured separately when their dimensions or governing requirements differ. Public Works' Street Use and Mapping bureau regulates and inspects use of sidewalks and streets, and building-permit coordination can also involve Public Works review of sidewalk and street grades, excavation and shoring.
For estimating, calculate the private driveway slab, sidewalk crossing, sidewalk replacement, curb-related work and pavement restoration as separate sections. For construction, use the current City permit, approved plan and Public Works requirements for any portion in the public right-of-way.
San Francisco concrete placements frequently require hot-weather planning. High concrete and ambient temperatures, direct sun, low relative humidity and wind can increase evaporation and shorten the time available for placing and finishing. The concrete supplier and contractor should coordinate mixture temperature, delivery timing, placement sequence and curing for the actual conditions.
A volume calculator cannot compensate for poor hot-weather logistics. For a larger driveway, patio or slab, plan how quickly trucks can discharge, whether a pump or other placement method is needed, and how curing will begin after finishing. Do not change water or admixture dosage without following the approved concrete mixture and supplier instructions.
Public-right-of-way concrete is not simply a material-volume problem. Public Works permitting staff review sidewalk and street grades, permit conditions and plans, and street inspectors check sidewalk and street construction for compliance with accessibility requirements, Title 24, permits and approved specifications.
When a project includes public-side concrete, keep private and public quantities separate. Use this calculator for cubic-yard estimating, but use current San Francisco Public Works requirements and the approved project documents for grade, accessibility, restoration and construction details.
San Francisco's PermitSF reform legislation signed in 2025 removed a local requirement that residential driveways and sidewalks be built to exceed the state's heavy-truck load standard. The reform took effect October 30, 2025. That change should not be read as permission to choose any slab thickness or reinforcement: the applicable state standards, local requirements, approved plans and actual project loading still control.
For estimating, enter the thickness shown on the approved design or selected by the responsible project professional. Do not reduce quantity solely because a former local load requirement was removed.
Measure the slab, footing or pier geometry, calculate exact cubic yards, then apply a realistic ordering allowance.
Common questions about cubic yards, driveways, patios, footings, bags, ready-mix and concrete planning in San Francisco.