Calculate the volume of concrete needed for a rectangular slab in cubic yards or cubic meters.
Should I order the exact amount of concrete calculated?
It is highly recommended to order 5-10% more concrete than you calculate. This extra amount, often called a "waste factor," accounts for uneven subgrade, spillage, and the small amount of concrete that may remain in the truck or wheelbarrow.
What do the numbers like 3000 PSI or 4000 PSI mean?
PSI stands for "Pounds per Square Inch" and measures the compressive strength of the concrete after it has fully cured (typically after 28 days). 3000-4000 PSI is a common strength for residential projects like driveways and patios. Higher PSI values are required for commercial applications or heavy-duty industrial floors.