Masonry & Footings Calculators

Footings carry the load of a structure into the ground, and masonry walls sit on them. The tools here estimate block counts, mortar, rebar and footing concrete, and the structural details such as depth, width and reinforcement come from the code and your soil.

Which tool answers which question

• Concrete Block (Cinder Block) Calculator: Wall length and height to cinder blocks needed, plus bags of mortar mix to lay them.
• Concrete Footing Calculator: Cubic yards and bags of concrete for continuous footings or round deck and pier footings.
• Mortar Mix Calculator: Bags of mortar mix for a brick or block wall, or thinset tile mortar by trowel size.
• Rebar Calculator: Rebar grid for a slab: bars each way, linear feet with laps, sticks to buy and weight.

Blocks, mortar and rebar

A standard concrete block is 8 by 8 by 16 inches, which covers about 0.89 square feet of wall face including the mortar joint, so a wall needs roughly 1.125 blocks per square foot. Mortar use depends on the joint size and the mix, and rebar is sold in set lengths and sizes, so the tool counts pieces and lap splices. Always add extra for breakage and cuts.

Footings

Footing depth and width depend on the frost depth, soil bearing capacity and the load, and the code or an engineer sets them. Footings must sit below the frost line in cold climates, or the ground can heave the structure. These tools estimate the concrete volume only, and they do not decide the design.

Common mistakes

• Guessing the footing size. Ask the building department or an engineer.
• Ignoring frost depth. Shallow footings can heave.
• Counting blocks without cuts. Openings and corners change the count.
• Skipping inspections. Footings are usually inspected before you pour.