What These Calculators Cover
Concrete and masonry are the backbone of most construction projects. Getting quantities wrong is costly: too little concrete means a cold joint in your slab, and too many blocks means wasted money sitting on a pallet. These calculators convert your project dimensions into exact material quantities.
Each calculator accounts for the specific variables that matter for its material type — slab thickness for concrete, bar spacing for rebar, block size for walls, and coverage rates for adhesives.
Each Calculator Explained
Concrete Slab Calculator
Calculates the volume of concrete in cubic yards for rectangular slabs, footings, and foundations. Enter length, width, and thickness to get the total volume plus an estimated bag count for smaller pours.
Use when: You're ordering ready-mix concrete for a driveway, patio, garage floor, or foundation. Also useful for estimating cost since concrete is priced per cubic yard.
Concrete Bags Calculator
Converts a concrete volume into the number of pre-mix bags you need. Choose between 40 lb, 60 lb, and 80 lb bag sizes. Shows total bags and total weight so you can plan for transport.
Use when: You're mixing concrete by hand for small projects like fence posts, mailbox bases, small pads, or repairs. For anything over 1 cubic yard, consider ordering ready-mix delivery instead.
Rebar Calculator
Calculates the number of reinforcing steel bars for a concrete slab. Enter slab dimensions and desired bar spacing (typically 12" or 18" on center). Shows total bar count, linear feet of rebar, and total weight in pounds.
Use when: You're reinforcing a concrete slab, footing, or wall. Rebar spacing requirements are often specified by local building codes, so check before choosing a spacing value.
Block Wall Calculator
Calculates the number of CMU (concrete masonry unit) blocks needed for a wall. Enter wall length, height, and block size. Includes an estimate for mortar bags based on standard joint thickness.
Use when: Building retaining walls, foundation walls, garden walls, or any block structure. Account for openings (doors, windows) by subtracting their area from the total wall area.
Mortar & Thinset Calculator
Calculates bags of adhesive for tile and brick projects. Select the product type (mortar, thinset, or grout), trowel notch size, and coverage area. Shows bags needed based on manufacturer coverage rates.
Use when: Tiling floors, walls, or showers. Also useful for brick veneer and stone installations. Trowel notch size significantly affects coverage, so match it to your tile size.
Related Guides
Bricks, Mortar and Block Fill: Estimating Different Materials
Collect separate inputs for brick faces, bedding mortar, and selected CMU cores before estimating an order.
Calculating Concrete Shapes and Screed Bag Yields
Measure solid steps, separate landings and floor thickness before converting each material to product-specific bags.
Tips for Concrete & Masonry Projects
- Always order concrete 5-10% extra — you can't easily add more once a pour has started, and uneven ground absorbs more than you expect.
- For small projects under 1 cubic yard, bags are practical. Above that, ready-mix truck delivery is significantly cheaper per yard.
- Rebar spacing affects structural integrity. Check your local building codes before choosing 12" vs 18" on center.
- Block walls need a solid footing. Calculate the footing separately using the concrete slab calculator.
- Mortar coverage varies by joint thickness. Standard 3/8" joints use less mortar than 1/2" joints. Factor this into your estimate.
Concrete & Masonry Guides
Common Tasks
Pour a Concrete Slab
Build a Block or Retaining Wall
Concrete & Masonry Calculators
All calculators in this category.
Concrete Slab Calculator
concrete
Estimate concrete volume in cubic meters and bag counts for slabs, footings, and pads based on length, width, and thickness.
Post-Hole Concrete Calculator
concrete
Estimate concrete volume and whole bags for round or rectangular post holes while subtracting the post displacement.
Brick & Mortar Calculator
concrete
Estimate single-wythe brick counts, mortar volume or product-coverage bags, allowances, and optional local material prices.
Concrete Block Fill Calculator
concrete
Estimate CMU core fill from a matched table or measured partial cores, with explicit cavity volume, ordering allowance, bag count, and optional local pricing.
Concrete Steps Calculator
concrete
Estimate solid level-base concrete step volume, an optional separate landing, allowance-adjusted concrete, whole bags, and an optional local bag price.
Concrete Driveway Cost Calculator
concrete
Build an editable itemized driveway estimate from specified slab/base quantities, supplier ordering, local quotes, and an exclusive all-in quote option.
Concrete Bags Calculator
concrete
Convert a concrete volume into the number of pre-mix bags you need, with options for common bag sizes and mix strengths.
Rebar Calculator
concrete
Calculate reinforcing steel bar count, total length, and weight for concrete slabs and footings based on spacing and bar size.
Block Wall Calculator
masonry
Estimate CMU blocks and mortar bags for masonry walls based on wall dimensions, block size, and joint thickness.
Mortar & Thinset Calculator
adhesives
Calculate bags of mortar or thinset adhesive needed for tiling and brickwork based on area, notch size, and coverage rate.
Retaining Wall Calculator
masonry
Calculate retaining wall blocks, cap blocks, backfill gravel, drain pipe, and filter fabric for CMU and landscape block walls.