Enter wall length and height to calculate exact 8×8×16 CMU block counts, courses, 80-lb mortar bags, core-fill concrete grout, and wall footing yardage.
| Material / Application | Standard Spec / Depth | Coverage / Weight | Field Note |
|---|---|---|---|
| Standard 8" × 8" × 16" CMU | 7.625" × 7.625" × 15.625" actual (+3/8" joint) | 1.125 blocks per sq ft (112.5 per 100 sq ft) | 0.25 cu ft grout per block (all cores filled) |
| 6" × 8" × 16" Light Block | 5.625" × 7.625" × 15.625" actual | 1.125 blocks per sq ft | 0.18 cu ft grout per block |
| 12" × 8" × 16" Structural CMU | 11.625" × 7.625" × 15.625" actual | 1.125 blocks per sq ft | 0.42 cu ft grout per block |
| 80-lb Type S Mortar Mix Bag | Yields ~0.85 cu ft wet mortar | Lays 30 – 35 standard 8×8×16 blocks | 3.2 bags per 100 blocks (including waste) |
Free cubic yard and tonnage calculator for gravel, concrete, mulch, asphalt, roofing, pavers, cinder blocks, topsoil, and paint. Multi-zone builder + printable estimate sheet.
Instant gravel calculator in tons, cubic yards, and 50-lb bags. Supports multiple driveway zones, compaction allowance, pea gravel vs #57 crushed stone densities, and bulk vs bag cost.
Free concrete calculator for slabs, patios, driveways, footings, and round sonotube post holes. Shows cubic yards, 80-lb and 60-lb bag counts, short-load truck fees, and rebar estimate.
Free mulch calculator and estimator: convert flower bed dimensions and tree rings into cubic yards, 2 cu ft bags, and 3 cu ft bags. Compares bagged vs bulk mulch delivery costs.
Free roofing calculator, roof pitch calculator, and roof slope multiplier. Calculates true roof square footage, roofing squares, architectural shingle bundles, underlayment, and cost.
Accurate asphalt calculator in US tons and cubic yards. Uses standard 145 lb/ft³ hot-mix density, roll-down compaction guide, cold-patch 50-lb bag count, and hot-mix plant cost.
Complete patio paver calculator: computes paver count for 4x8 brick, 6x9, 12x12, 16x16, and 24x24 slabs plus crushed gravel base tons, leveling sand bags, and polymeric sand.
Free paint coverage calculator: enter wall dimensions, doors, windows, coats, and surface texture to get exact gallons, liters, primer needs, and 5-gallon vs 1-gallon can savings.
Free topsoil calculator and sod calculator: convert lawn or raised garden bed dimensions into cubic yards, tons, 40-lb bags, and sod pallets.
With a standard 3/8-inch mortar joint, a nominal 8" × 16" concrete block has a face area of 128 square inches (0.8889 sq ft). Dividing 144 by 128 gives exactly 1.125 blocks per square foot (or 112.5 blocks per 100 sq ft of wall).
One 80-lb bag of pre-blended Type N or Type S masonry mortar lays roughly 30 to 35 standard 8×8×16 blocks. Plan on 3 to 3.5 bags of 80-lb mortar per 100 blocks.