Construction Math: Area, Volume & Material Quantities
# Construction Math: Area, Volume & Material Quantities
Once you can measure accurately (see the tape-measure and fractions lessons), the next step is turning measurements into **how much material you need**.
## Area — for surfaces
**Area = length × width**, in **square feet**. Use it for flooring, drywall, paint, roofing, and tile.
- Example: a 12 ft × 10 ft room = **120 square feet** of floor.
## Volume — for fill
**Volume = length × width × depth**, in **cubic feet** (or cubic yards for concrete).
- **1 cubic yard = 27 cubic feet.**
- Example: a slab 10 ft × 10 ft × 4 inches (0.33 ft) ≈ 33 cubic ft ≈ **1.2 cubic yards** of concrete.
## Linear feet — for runs
For trim, baseboard, pipe, and lumber, you measure **linear feet** — the length along the run.
## Waste factor
Always order a little **extra** (a percentage on top — often 5–10%) for cuts, mistakes, and damage.
## Why it matters
Good quantity math means you **order the right amount** — not too little (delays) or too much (wasted money).
**Takeaway:** Turn measurements into material: area for surfaces, volume for fill, linear feet for runs — and always add a waste factor.
> *Educational overview — practice the hands-on skills with real tools and materials.*
