Question 1

How do I calculate concrete for round columns or posts?

Accepted Answer

Calculate volume using πr²h (pi × radius² × height). For a 12" diameter, 8 ft tall column: radius is 6" (0.5 ft), so π × 0.5² × 8 = 6.28 cubic feet or 0.23 cubic yards. This calculator does the math automatically.

Question 2

How much concrete do I need for stairs?

Accepted Answer

Concrete stairs volume = (tread depth × tread width × number of treads ÷ 2) + (riser height × tread width × riser thickness). Complex shapes benefit from this calculator which handles the geometry automatically.

Question 3

How thick should a concrete countertop be?

Accepted Answer

Standard concrete countertops are 1.5" to 2" thick. Thicker countertops (2.5"-3") are stronger but heavier and more expensive. Thin countertops need rebar or mesh reinforcement for strength.

Question 4

How much does a yard of concrete cost?

Accepted Answer

Concrete costs $125-200 per cubic yard depending on location, concrete strength, and additives. Delivery fees add $50-100. Small loads (under 4 yards) may have short-load fees adding $50-100 per yard.

Question 5

Should I order extra concrete?

Accepted Answer

Yes! Order 5-10% extra to account for spillage, uneven ground, measurement errors, and waste. Concrete trucks cannot return unused concrete, so ordering slightly over is better than running short mid-pour.

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