Concrete Block (CMU) Calculator – Wanjaaro Material & Cost Calculator
Estimate standard CMU blocks, core-fill grout volume, mortar bags, and vertical rebar. Free, instant deterministic calculations with waste margin, material takeoffs, and contractor cost breakdown.
Category: Concrete & Masonry
Last Modified: 2026-10-11
Available Building Material Calculators
- Concrete Slab & Footing Calculator – Calculate volume in cubic yards, pre-mixed bags (40, 60, 80 lb), and rebar grid requirements.
- Brick & Mortar Calculator – Calculate total modular, king, or queen bricks, mortar bags (Type N/S), and tons of sand.
- Concrete Block (CMU) Calculator – Estimate standard CMU blocks, core-fill grout volume, mortar bags, and vertical rebar.
- Wall Framing & Stud Calculator – Calculate common studs, double top plates, bottom sill, headers, corners, and board feet.
- Plywood & OSB Sheathing Calculator – Determine 4x8 / 4x10 sheets for walls, subfloors, and roof decks plus framing nail counts.
- Drywall & Sheetrock Calculator – Calculate 4x8, 4x10, 4x12 drywall sheets, joint compound buckets, screws, and tape rolls.
- Paint & Primer Coverage Calculator – Estimate gallons of wall/ceiling paint and primer with window and door deduction.
- Roofing Shingle & Pitch Calculator – Calculate roofing squares, architectural bundles, pitch multipliers, felt, and ridge caps.
- Tile, Grout & Flooring Calculator – Calculate square footage, tile boxes with waste, grout weight (lbs), and thin-set bags.
- Construction Cost & Budget Estimator – Estimate total project budget with material subtotal, labor rates, GC markup, and contingency.
Frequently Asked Questions
How many 8x8x16 concrete blocks (CMU) are in a square foot of wall?
A standard CMU block has nominal dimensions of 8" high by 16" long (actual 7-5/8" × 7-5/8" × 15-5/8" to accommodate 3/8" mortar joints). The face area is 128 square inches (8/12 × 16/12 = 0.8889 sq ft). Dividing 1 by 0.8889 yields exactly 1.125 blocks per square foot (or 112.5 blocks per 100 square feet of wall).
What type of mortar should be used for CMU block foundation walls?
Type S mortar is recommended for below-grade foundation walls, retaining walls, and load-bearing CMU structures because it offers high compressive strength (minimum 1,800 psi) and superior flexural bond strength compared to Type N mortar.