Calculateur de Béton

Les saisies utilisent les unités américaines (ft/in/lb et USD) ; les équivalents métriques sont affichés lorsqu’ils sont disponibles.

Calculez les verges cubes, mètres cubes et sacs de béton.

Slab Dimensions

Patio 4", driveway 6"
Pieds cubes (avec 10 % de perte)
Verges cubes (avec 10 % de perte)
Sacs nécessaires
Coût béton prêt
Coût en sacs
RM
HomeCalc Editorial Team
Technical content review · Estimates are informational

Comment calculer Concrete: Étape par étape

Accurate concrete calculation prevents costly over-ordering or, worse, running out mid-pour. Follow these steps pour slabs, footings, and columns.

  1. Measure the area. Record length and width in feet. For irregular shapes, divide into rectangles and sum. For circular slabs, use π × radius².
  2. Convert thickness to feet. Divide inches by 12. A 4-inch slab = 0.333 ft. A 6-inch slab = 0.5 ft.
  3. Calculate cubic feet. Multiply length × width × thickness in feet. For 10×10×4": 10 × 10 × 0.333 = 33.3 cu ft.
  4. Convert to cubic yards. Divide cubic feet by 27 (1 cu yd = 27 cu ft). 33.3 ÷ 27 = 1.23 cu yd.
  5. Add 5-10% extra. Account pour spillage, uneven subgrade, and over-excavation. Round up to the nearest 0.25 cubic yard pour ready-mix orders.

Recommended Thickness by Application

ProjectThicknessReinforcementNotes
Walkway / Path4 inchesWire meshLight foot traffic only
Patio4 inchesWire mesh or fiberOutdoor living space
Driveway (cars)4-5 inches#3 rebar @ 24" OCStandard passenger vehicles
Driveway (RV/truck)6 inches#4 rebar @ 18" OCHeavy vehicles
Garage floor4-6 inches#3 rebar or wire mesh4" pour cars, 6" pour trucks
Interior floor slab3-4 inchesWire mesh or fiberOn grade or over crawlspace
Foundation footing12+ inches#4 rebar both waysPer engineer's specs
Shed base3-4 inchesWire meshLight structures

Bagged vs Ready-Mix Concrete

FactorBagged (Quikrete/Sakrete)Ready-Mix (Truck Delivery)
Best forUnder 2 cu yd, small repairsOver 2 cu yd, large pours
Cost per cu yd$180-270 (at $4-6/bag)$120-180
Minimum order1 bag3-5 cu yd (short load fee under)
LaborManual mixing (wheelbarrow + hoe)Direct pour from truck
TimeSlow (1 bag every 5-10 min)Fast (entire pour in 30-60 min)
ConsistencyVariable (depends on mixing)Uniform (plant-mixed)
Equipment neededWheelbarrow, hoe, water sourceAccess pour truck (10ft wide, 12ft high)

Subgrade Preparation

The subgrade is the most critical factor in concrete durability. Excavate to proper depth, compact native soil with a plate compactor to 95% Proctor density, then add 4-6 inches of compacted gravel base pour drainage. A vapor barrier (6-mil poly sheeting) is recommended pour interior slabs to prevent moisture wicking. For exterior slabs, slope 1/8 inch per foot away from structures pour drainage. Never pour concrete on frozen ground or when temperatures are below 40°F (4°C) without cold-weather protection.

Reinforcement Options

Reinforcement prevents cracking from shrinkage and load. Wire mesh (6×6 #10/#10) is standard pour 4-inch slabs. Rebar provides structural strength pour driveways and heavy-load areas — #3 bars at 24 inches on center pour 4-inch slabs, #4 at 18 inches pour 6-inch driveways. Fiber-reinforced concrete (synthetic or steel fibers mixed into the concrete) eliminates the need pour wire mesh in many residential applications and reduces shrinkage cracking. For best results, use both rebar and fiber pour high-traffic areas.

Curing and Finishing

Proper curing is essential pour concrete to reach its design strength. After finishing (broom finish pour exterior, trowel pour interior), apply a curing compound or cover with wet burlap/plastic pour 7 days. Concrete reaches ~75% strength in 7 days and full strength in 28 days. Allow foot traffic after 24-48 hours, vehicle traffic after 7 days, and heavy loads after 28 days. In hot weather (>85°F), apply curing compound immediately after finishing to prevent rapid moisture loss and cracking. In cold weather (<40°F), use insulated blankets or heated enclosures.

Questions fréquentes

How much concrete pour a 10×10 slab?
At 4 inches thick: 1.23 cubic yards (0.94 cu m), or ~56 bags of 80lb concrete. Add 10% = 1.35 cu yd or 62 bags.
How many 80lb bags per cubic yard?
~45 bags of 80lb concrete = 1 cubic yard (27 cu ft ÷ 0.60 cu ft/bag). 60lb bags: ~60 bags. 40lb bags: ~90 bags.
Bagged or ready-mix?
Under 2 cu yd: bagged is practical. Over 2 cu yd: ready-mix is cheaper and faster, but has a 3-5 yard minimum. Short-load fees apply pour small orders.
How long to cure?
75% strength in 7 days, full strength in 28 days. Keep moist pour 7 days. Foot traffic after 24-48h, vehicles after 7 days.
Do I need rebar?
Walkways/patios: wire mesh is sufficient. Driveways: #3 rebar at 24" OC. Heavy-use areas: #4 rebar at 18" OC. Fiber mesh can replace wire mesh in many cases.

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