Calculator collection
Block, rebar & mix calculators
Concrete blocks, rebar grids and cement : sand : stone mix ratios.
Brick CalculatorFree brick calculator. Enter wall size, openings, brick size (modular, queen, king, Norman) and joint to get bricks, bricks per square foot and mortar.Open calculator Cement vs ConcreteCement vs concrete: cement is the powder binder; concrete is cement plus sand, gravel and water. See how much cement a yard needs and which one to buy.Open calculator Cinder Block Weight CalculatorA standard 8x8x16 cinder block weighs about 40 lb (18 kg); lightweight blocks about 26 lb. Weight chart by size, per pallet, and a load calculator.Open calculator 
Concrete Block CalculatorFree concrete block calculator. Enter wall length, height and openings to get CMU or cinder block counts, courses and blocks per course with breakage.Open calculator 
Concrete Mix Ratio CalculatorConcrete mix ratio calculator: pick 1:2:3, 1:2:4 or 1:1.5:3 and get 94 lb bags of cement, sand and gravel in ft³, yd³ and m³, plus water.Open calculator Concrete PSI GuideConcrete psi explained: IRC Table R402.2 minimums for slabs, garage floors and porches, ACI 318 strength by exposure class, and what psi bagged mix reaches.Open calculator 
Mortar CalculatorFree mortar calculator. Enter how many concrete blocks or bricks you are laying to get the number of 80 lb bags of mortar mix, with waste.Open calculator 
Rebar CalculatorFree rebar calculator for concrete slabs. Enter size, grid spacing and bar size to get bars each way, total length, 20 ft sticks and weight for #3 to #8.Open calculator Rebar Size ChartRebar size chart for #3 to #18 bars: diameter in inches and mm, cross-section area, weight in lb/ft and kg/m, stick weights, and Canadian metric 10M to 55M.Open calculator Retaining Wall CalculatorFree retaining wall block calculator. Enter wall length, height and block face size to get blocks, caps, base rock and drain rock in yd³, tons and m³.Open calculator Stucco CalculatorFree stucco and cement plaster calculator. Enter wall area, openings and coat thickness to get 80 lb bags of base coat and finish coat, volume and weight.Open calculator Wire Mesh CalculatorFree welded wire mesh calculator. Enter slab size, sheet or roll size, mesh style and overlap to get sheets or rolls to buy, mesh area and steel weight.Open calculator FAQ
Frequently asked questions
How many concrete blocks per square foot of wall?
A standard 8 × 16 in nominal block face covers 128 in², so 144 ÷ 128 = 1.125 blocks per ft² of wall. Add a few percent for cuts and breakage.
How much does rebar weigh per foot?
Nominal weights from Gerdau are #3 0.376, #4 0.668, #5 1.043 and #6 1.502 lb/ft. Common stock lengths are 20, 30, 40 and 60 ft.
How many blocks does an 80 lb bag of mortar lay?
QUIKRETE's Mortar Mix 1102 data sheet says one 80 lb bag lays up to 13 standard 8 × 8 × 16 in blocks or 37 standard bricks.
What is a concrete mix ratio?
It is the proportion of cement : sand : stone by volume, such as 1:2:3. The mix ratio calculator turns a ratio and volume into cement bags, sand and stone quantities.
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