Work out how much concrete, steel and asphalt your project needs, and what it will cost, before you order. Each calculator turns your measurements into cubic yards, bags, bars or tons, with a worked example on every page.
Concrete calculators
- Concrete calculator: cubic yards and bags for slabs, walls and round columns.
- Concrete footing & sonotube calculator: bags per post hole and in total, with the post taken out.
- Rebar calculator: bars each way, total length, weight and tie points for a slab grid.
- Concrete cost calculator: ready-mix compared with bags, including fees, base and labor.
Asphalt calculators
- Asphalt calculator: tons of asphalt for a driveway or path.
- Asphalt driveway cost calculator: asphalt, base, labor, removal and fees in one breakdown.
Which calculator should I use?
| Your project | Calculator | Typical size |
|---|---|---|
| Patio, walkway or shed slab | Concrete | 4 in thick |
| Driveway slab | Concrete | 4–6 in thick |
| Fence or deck posts | Concrete footing | Hole about 3 times the post width |
| Steel grid in a slab | Rebar | Bars 12–18 in apart |
| Asphalt driveway | Asphalt | 2–3 in over a gravel base |
| Comparing prices | Concrete cost or asphalt driveway cost | Use local quotes |
Before you order
- One cubic yard of concrete is 27 cubic feet, which takes 45 bags of 80 lb or 60 bags of 60 lb.
- For more than about a cubic yard of concrete, ready-mix delivery is usually easier than mixing bags. Ask about minimum orders and short-load fees.
- Both concrete and asphalt need a compacted gravel base. The crushed stone calculator works it out.
- See How We Calculate for the formulas and values we use.