Concrete Glossary: Terms Used in Our Calculators
Short definitions of the concrete terms used across our calculators and guides, each linked to the page that uses it.
Concrete Terms A to Z
- Base course: the 4 in layer of gravel, crushed stone or sand under a slab (2021 IRC R506.2.2). See gravel under concrete slab.
- Cubic yard: 27 cubic feet (0.7646 m³), the unit ready-mix is sold in. See concrete yard calculator.
- Curing: keeping new concrete moist and warm for 3 to 7 days (NRMCA). See concrete drying and curing time.
- Monolithic slab: a slab and its footing poured in one piece. See the monolithic pour calculator.
- PSI: compressive strength in pounds per square inch at 28 days. See the what psi concrete to use.
- Ready-mix: concrete mixed at a plant and delivered in a truck mixer of 8 to 12 yd³.
- Sonotube: Sonoco's brand of round cardboard concrete form. See the concrete tube calculator.
- Vapor retarder: a 10-mil sheet under house slabs (IRC R506.2.3).
- Waste factor: extra concrete ordered for spills and uneven subgrade; 4 to 10 percent (NRMCA), 10% in our tools.
- Yield: the volume one bag makes, such as 0.6 ft³ for an 80 lb bag.
Last reviewed 2026-11-05. Numbers come from our tested engine; see how we calculate and our sources.