Plan Concrete Yards, Bags & Project Quantities in Durham, North Carolina
Use this Concrete Calculator in Durham, NC to estimate concrete for slabs, patios, driveways, sidewalks, parking pads, footings, piers and posts. Calculate cubic yards, cubic feet and cubic meters, add a project allowance, compare bag quantities and enter your own Durham ready-mix price for a simple material-cost estimate.
Estimate slabs and driveways, continuous footings, round piers/posts, or convert a known concrete volume into bags and cost.
Estimate patios, driveway slabs, parking pads, sidewalks and other rectangular flatwork.
Quantity estimate only. Thickness, reinforcement, joints, subbase, drainage and permit requirements must follow the actual Durham project.
Estimate continuous footing, grade-beam or trench-fill volume from total length, width and depth.
Use approved/project footing dimensions. Soil conditions, loads, reinforcement and structural design are separate issues.
Calculate concrete for straight cylindrical piers, drilled holes and round post footings.
Straight-cylinder estimate only. Required pier/post diameter, depth, bearing and uplift resistance must be determined separately.
Convert a known volume into cubic yards, cubic feet, cubic meters, bag quantities and optional material cost.
Verify actual bag yield and obtain a current supplier quote. Delivery, short-load, pumping, access and waiting charges are separate unless included.
A Concrete Calculator in Durham helps homeowners, contractors and estimators calculate ready-mix or bagged concrete for patios, driveways, parking slabs, sidewalks, garage floors, footings, piers and post foundations throughout Durham and the surrounding Triangle area. The basic formulas are universal, but local permit rules, right-of-way requirements, Piedmont weather and site conditions still matter.
The calculator above focuses on material quantity rather than structural design. It leaves thickness, footing dimensions, pier depth and supplier price as project-specific inputs so the calculation stays useful without pretending one standard detail fits every Durham property.
Estimate patios, driveways, sidewalks and parking slabs from measured dimensions.
Calculate continuous footing and grade-beam quantity from approved dimensions.
Estimate round pier/post-hole concrete with optional post displacement.
Hot summers, thunderstorms and occasional freezes can affect placement and curing plans.
For a rectangular slab, multiply length by width by thickness. Convert thickness from inches to feet before multiplying. The result is cubic feet. Divide cubic feet by 27 to get cubic yards.
Use actual dimensions from plans, forms or field measurements.
Divide slab thickness, footing width and footing depth by 12.
Use rectangular or cylindrical geometry.
Divide cubic feet by 27.
Use a margin appropriate to actual field conditions.
Length and width are in feet; thickness is entered in inches.
One cubic yard contains 27 cubic feet.
Assumes a constant rectangular cross-section.
Convert diameter and depth to feet before calculating.
Flatwork is one of the most common reasons to use a Durham concrete calculator. Patios, garage floors, parking slabs, private walks and driveway sections can usually be divided into rectangles. If one area has a different thickness, calculate it separately.
A 200-square-foot slab at 4 inches thick contains about 2.47 cubic yards before allowance. At 6 inches thick, the same plan area contains about 3.70 cubic yards. Those numbers compare volume only; they are not structural thickness recommendations.
| Area | 4 in | 5 in | 6 in | Purpose |
|---|---|---|---|---|
| 100 ft² | 1.23 yd³ | 1.54 yd³ | 1.85 yd³ | Volume comparison |
| 200 ft² | 2.47 yd³ | 3.09 yd³ | 3.70 yd³ | Volume comparison |
| 400 ft² | 4.94 yd³ | 6.17 yd³ | 7.41 yd³ | Volume comparison |
| 600 ft² | 7.41 yd³ | 9.26 yd³ | 11.11 yd³ | Volume comparison |
Geometry examples only; not thickness recommendations.
Driveways can widen near the garage, include parking pads or transition to a public street through the right-of-way. Divide irregular private areas into rectangles and add the volumes. If a driveway apron or approach uses a separate public detail, calculate it as a separate section.
Durham Public Works states that a right-of-way permit is required for all construction in the ROW and, in some cases, for construction on private property. The City specifically includes driveways and sidewalks in the permit scope. The permit page also notes that permits can expire 90 days after issuance if an inspection has not been requested.
For a dedicated parking slab workflow, use the Concrete Parking Pad Calculator.
The City’s current Right-of-Way Permits page is a key local source for driveway and sidewalk concrete. It states that ROW permits cover construction including driveways, sidewalks, water, sewer, storm drainage and irrigation. This is important when concrete extends beyond the private parcel or interacts with public infrastructure.
Durham’s site-plan standard notes also identify both City of Durham and NCDOT driveway/encroachment permit possibilities depending on the project location. That means a driveway connecting to a state-maintained road can follow a different path from one connecting to a City-maintained street.
Durham’s Planning & Infrastructure Inspections page states that sidewalks and pedestrian ramps in the City are to be constructed to PROWAG requirements. It also says inspectors check subgrade firmness and forms and notes a minimum of 6 inches of concrete for the inspected sidewalk condition described on that page.
This does not mean every private slab should be 6 inches thick. It means public sidewalk work needs to follow the applicable City standard and inspection requirements rather than a generic online slab assumption.
Durham’s current North Carolina Building Codes page states that the 2018 NC Codes, effective January 1, 2019, are currently effective. The North Carolina Office of State Fire Marshal has published the 2024 NC State Building Code, but its mandatory effective date has been delayed.
An official OSFM interpretation issued in December 2025 stated that the 2018 North Carolina State Building Code remained effective at that time and that the 2024 code could be used in its entirety as an alternative but was not yet mandatorily effective. Durham’s current code page continues to identify the 2018 code set as currently effective.
Concrete that is part of a building foundation, structural addition, garage, retaining system or other regulated work can involve code provisions that go far beyond cubic yards. Use current City and State guidance for the permit date.
Footing quantity is calculated from total run length × width × concrete depth. Use approved dimensions from project drawings or the qualified designer. Earth-formed trenches can consume more concrete than perfect theoretical geometry if excavation is oversized or sidewalls collapse.
Foundation design in Durham can involve soil conditions, building loads, reinforcement, drainage and local site constraints. The calculator intentionally does not choose footing width, footing depth or foundation type.
Round piers and post holes use cylindrical geometry. Enter diameter, depth and count. If a square or round post occupies the full entered depth, the calculator can subtract a simplified post-displacement volume.
Fence posts, deck supports, porch posts and structural piers do not share one universal size. Use the actual project-required dimensions first, then calculate quantity. For specialized tools, use the Concrete Fence Post Calculator or Concrete Pier Size Calculator.
Durham shares the Raleigh-Durham climate region. National Weather Service Raleigh climate resources show that the Triangle has warm to hot summers and a humid warm-season climate. Hot, sunny or breezy conditions can increase evaporation from fresh concrete and reduce finishing time.
The cubic-yard calculation itself does not change with temperature. What changes is the placement plan: delivery spacing, crew size, curing, access and protection should respond to the actual weather forecast and the concrete specification.
Coordinate trucks and finishing crews so concrete is not delayed during hot weather.
Heavy rain can change excavation and subgrade conditions before the pour.
NWS freeze climatology shows the region does experience freezing conditions, so cold-weather planning can still matter.
North Carolina Piedmont storms can produce significant rainfall. Rain does not change the intended geometry, but it can soften subgrade, erode edges, widen footing trenches or create low spots that consume extra concrete.
If heavy rain falls after final excavation or grading, remeasure important dimensions before placing an order. Drainage design and stormwater requirements are separate from volume calculation, but they can affect slab elevations, slopes and site preparation.
Durham winters are milder than northern climates, but freezes still occur. NWS Raleigh publishes 1991–2020 frost and freeze climatology for the region. Concrete placed during cold conditions may require different protection and curing procedures than a warm-weather pour.
Do not assume that a mild annual climate eliminates cold-weather concerns. Check the forecast and project requirements near the pour date, especially for overnight temperatures.
Bagged concrete can be practical for a few post holes or a small repair. This calculator uses approximate planning yields of 0.30 ft³ for a 40 lb bag, 0.45 ft³ for a 60 lb bag and 0.60 ft³ for an 80 lb bag. Always verify the actual product label.
Several cubic yards often favor ready-mix because hand mixing becomes labor intensive. Ask the supplier about minimum loads, short-load fees, delivery range, waiting time, truck access and pump requirements.
A single “Durham concrete price per yard” can become outdated quickly. Mix design, strength, admixtures, order quantity, delivery distance, short-load charges, pumping, access and waiting time can all change real project cost.
The calculator leaves the price input editable so you can use a current supplier or contractor quote.
Labor, reinforcement, formwork, excavation, permits, pumping, testing and tax are separate unless included in the quote.
Suppose a patio measures 20 feet by 12 feet and is 4 inches thick. The plan area is 240 square feet. Four inches equals one-third of a foot, producing about 80 cubic feet.
Divide 80 by 27 to get about 2.96 cubic yards. With a 10% allowance, planned quantity becomes about 3.26 cubic yards. Enter a current Durham supplier quote to estimate the simple material value.
This example demonstrates geometry only. It does not determine whether 4 inches is the correct structural thickness.
Measure the actual section, convert inches to feet, calculate cubic feet and divide by 27.
Measure: use actual project dimensions.
Convert: inches ÷ 12 before multiplying by feet.
Calculate: use rectangular or cylindrical geometry.
Order: cubic feet ÷ 27, then add your allowance.
Common questions about cubic yards, driveways, sidewalks, permits, North Carolina codes, weather, bags and concrete cost in Durham.