Estimate how many concrete blocks and bags of mortar your wall needs. Each dimension has its own unit selector (in/ft/yd/m).
Concrete masonry units (CMU) are estimated by wall area. Measure each wall's length and height (any unit), subtract openings, then multiply the net area by blocks-per-square-foot. A standard 8x8x16 block needs about 1.125 per sq ft - use the preset. Add about 5% for breakage, and plan roughly three 80-lb mortar bags per 100 blocks.
Use the concrete block calculator for CMU wall planning and quick material checks. It estimates block count from wall area, selected block coverage and waste, then adds mortar bag cost.
Start with the calculator that matches how your material is sold: area, length, volume, count, weight or electrical load. Enter one work area at a time, use the unit selector beside each measurement, then review the order quantity and cost fields before comparing supplier quotes.
Most calculators can save the current estimate in your browser, reload named estimates, print a copy, switch to dark mode or create a shareable link. Those tools are intended for planning and communication; always confirm final quantities, coverage rates, density, code requirements and pricing with the supplier or contractor responsible for the work.