8 calculators
Concrete & Masonry Calculators
Free concrete and masonry calculators: estimate concrete yards and bags, slabs, footings, blocks, bricks, mortar and rebar, with waste allowance and cost.
Which concrete or masonry calculator do you need?
- Any shape of pour (slabs, walls, columns, post holes, or several at once): the concrete calculator gives cubic yards, ready-mix and bags.
- A patio, driveway or shed base: the concrete slab calculator adds typical thicknesses by use and the gravel base underneath.
- A small job in bags, such as fence posts or steps: the concrete bag calculator compares 40, 50, 60 and 80 lb bags side by side.
- Foundations: the concrete footing calculator handles continuous footings, pads and piers.
- Walls: the concrete block and brick calculators count units, pallets and mortar from your wall sizes.
- Mortar on its own: the mortar calculator works from a unit count or wall area.
- Reinforcement: the rebar calculator counts bars, laps, ties and weight for a slab grid.
Planning a concrete job
Concrete is ordered by volume: length × width × thickness, converted to cubic yards (divide cubic feet by 27) or cubic meters. Two things catch people out. First, ground is never perfectly flat, so add 5–10% for low spots, form bulge and spillage. Second, you can only buy concrete in whole bags or in a supplier’s ¼ or ½ yard steps, so the amount you pay for is always a little more than the exact volume. Every calculator here shows the exact volume, the allowance and the rounded purchase separately, so you can see where each number comes from.
For pours under about a cubic yard, bagged concrete mixed on site is usually practical; 45 bags of 80 lb make one yard. Beyond that, a ready-mix truck is normally cheaper per yard, far less work, and gives one consistent batch. Ask suppliers about minimum orders and short-load fees before you decide.
Planning brick and block work
Masonry is counted by area. Each brick or block, plus its share of the mortar joint, covers a fixed area: a standard 8 × 16 in block with 3/8 in joints covers 0.89 ft² (1.125 blocks per square foot), and a modular brick about 0.146 ft² (roughly 6.9 per square foot). Subtract doors and windows, add 5–10% for cuts and breakage, and round up to whole units or pallets. Mortar depends on how units are bedded: bricks are fully bedded, while hollow blocks are usually bedded only on their face shells, so a block wall uses far less mortar per unit than a brick wall.
What these calculators do not do
They estimate quantities and cost. They do not size footings, choose slab thicknesses for a specific load, design reinforcement or check building codes. Thicknesses and rebar patterns mentioned on these pages are common starting points; your plans, a structural engineer or your local building department have the final say.