How to Calculate Concrete for a Semicircular Driveway

A semicircular driveway can increase a home's value.

A semicircular driveway adds timeless elegance and style to a home with an expansive front yard. To accurately estimate the cost of paving a concrete driveway, you must calculate the total volume of concrete needed for the project. Knowing how much concrete to buy for your semicircular driveway will keep your construction costs under control.

Things You'll Need

• Measuring tape
• Calculator

Instructions

1. Measure the radius of the outer semicircular arc in feet, and call this number X. The radius is half of the diameter.

2. Measure the radius of the inner semicircular arc in feet, and call this number Y.

3. Measure the depth of the concrete driveway in feet, and call this number Z. For reference, 4 inches = 0.333 feet, 6 inches = 0.5 feet and 8 inches = 0.667 feet.

4. Plug the variables X, Y and Z into formula V = (3.14159)*(0.5)*Z*(X^2 - Y^2) to find the total volume of concrete in cubic feet.

5. Convert cubic feet to cubic yards by dividing by 27. That gives you the amount of concrete needed for your driveway.

References

• Math Open Reference: Area of an Annulus
• Math Open Reference: Volume of a Cylinder