Concrete & Masonry Calculators

Estimate concrete, block, brick, mortar, pavers and rebar with calculators that show the formula, use real material data, and build in a waste factor. Free, no sign-up, and built to be checked.

Concrete pours

Volume in cubic yards and bags

Estimating a concrete pour comes down to volume: length times width times thickness, converted to cubic yards. These calculators handle the common shapes and tell you whether to order ready-mix or buy bags, with a waste allowance built in.

Masonry walls

Block and brick counts, courses and mortar

Masonry is counted by the unit. We work out how many blocks or bricks cover your wall area, how many courses high it stands, and the bags of mortar to lay them, so you order the right amount the first time.

Materials & reinforcement

Mortar, pavers and rebar

The pieces that go with the main pour: the mortar that binds masonry, the pavers for a patio, and the rebar grid that controls cracking in slabs and footings.

Guides

How-to and cost guides that funnel into the calculators
Brick Calculator: How Many Bricks Do I Need?GuideBrick Wall Cost Per Square FootGuideConcrete Block Wall Cost Per Square FootGuideConcrete Calculator: Cubic Yards, Bags and CostGuideConcrete Mix Ratio: Cement, Sand and Aggregate by StrengthGuideConcrete Slab Cost Per Square FootGuideCost to Build a Brick WallGuideCost to Pour a Concrete SlabGuideHow to Size Deck FootingsGuideHow Deep Should a Footing Be?GuideHow Long Does Concrete Take to Cure?GuideHow Many 80 lb Bags of Concrete in a Yard?GuideHow Many Bags of Concrete in a Yard?GuideHow Many Bags of Concrete per Fence Post?GuideHow Many Bags of Mortar Per 100 Block?GuideHow Many Bricks Do I Need?GuideHow Many Bricks Per Square Foot?GuideHow Many Bricks to Build a House?GuideHow Many Cinder Blocks Do I Need?GuideHow Many Concrete Blocks Do I Need?GuideHow Many Pavers Do I Need?GuideHow Many Pavers for a 10x10 Patio?GuideHow Many Retaining Wall Blocks Do I Need?GuideHow Much Concrete Do I Need?GuideHow Much Do Concrete Steps Cost?GuideHow Much Does a 12x12 Concrete Slab Cost?GuideHow Much Does a 20x20 Concrete Slab Cost?GuideHow Much Does a 30x40 Concrete Slab Cost?GuideHow Much Does a Cinder Block Wall Cost?GuideHow Much Does a Concrete Driveway Cost?GuideHow Much Does a Concrete Patio Cost?GuideHow Much Does a Concrete Sidewalk Cost?GuideHow Much Does a Paver Patio Cost?GuideHow Much Does a Paver Walkway Cost?GuideHow Much Does a Yard of Concrete Weigh?GuideHow Much Does Concrete Cost?GuideHow Much Does Rebar Cost?GuideHow Much Mortar Do I Need?GuideHow Much Paver Base Do I Need?GuideHow Much Rebar Do I Need?GuideHow Thick Should a Concrete Slab Be?GuideHow Thick Should a Garage Slab Be?GuideHow to Build a Concrete Block WallGuideHow to Build a Retaining WallGuideHow to Calculate ConcreteGuideHow to Lay PaversGuideHow to Mix ConcreteGuideHow to Pour a Concrete SlabGuideHow Wide Should a Footing Be?GuideMortar Mix Ratio: Type N, S, M and O ExplainedGuideRebar Size Chart: Diameters, Areas and WeightsGuideRebar Weight Per FootGuideRetaining Wall Cost Per Square FootGuideHow Much Does a Retaining Wall Cost?GuideRetaining Wall Estimator: How to Calculate Blocks and CostGuideStandard Brick SizesGuideStandard Concrete Block SizesGuideTypes of ConcreteGuide

How to estimate concrete

Concrete is sold by the cubic yard for ready-mix or by the bag for pre-mixed. Every estimate starts with volume: for a flat pour it is length times width times thickness, and for a round column it is the area of the circle times the height. Convert the thickness to feet, multiply through, then divide by 27 to get cubic yards. Above about one cubic yard, ready-mix delivered is cheaper and faster than mixing bags by hand, so the concrete calculator and its shape-specific siblings tell you which way to go and round ready-mix up to the nearest quarter yard, which is how it is ordered.

Always add a waste allowance. Trench bottoms are uneven, forms leak a little, and you cannot top up a pour once the truck leaves, so 5 to 10% extra and rounding up is normal rather than wasteful. For structural pours like driveways and footings, plan reinforcement too: size the rebar grid with the rebar calculator and follow your local code.

How to estimate masonry

Masonry is counted by the unit, not by volume. A standard concrete block covers about 0.889 square feet, so a square foot of wall takes 1.125 blocks; a modular brick covers about 21 square inches, or 6.86 bricks per square foot. Multiply your wall area by the units per square foot, add waste for breakage and cuts, and round up. The block and brick calculators also give the courses and the bags of mortar, using verified pre-mixed coverage of about 8 to 9 bags per 100 blocks and 28 per 1000 bricks.

Walls need more than units. Lay them on a level, cured footing, keep your mortar joints a consistent 3/8 inch, and reinforce tall or load-bearing walls with rebar in grouted cells. Retaining walls add drainage and a buried base course, and brick veneer needs ties, flashing and weep holes. Each calculator covers the specifics, and the figures are cross-checked against manufacturer spec sheets and standards like ASTM C90 and C270.

Why these calculators

Every calculator here shows its formula, so you can check the math instead of trusting a black box. The numbers come from real material data, an 80 lb concrete bag yields about 0.60 cubic feet, drawn from standards and manufacturer figures rather than round guesses, and every formula is verified with automated tests on each build. Enter feet and inches the way you measure on site, or switch to metric, share or print your result, and order with confidence.