CONSTRUCTION CALCULATOR
Concrete Calculator
Calculate concrete in cubic yards or cubic meters for slabs, pads, rectangular footings and post holes. Combine multiple pours, compare ready-mix with 40 lb, 60 lb and 80 lb bags, add extra material and estimate cost before you order.
SLAB / PAD
Project measurements
Calculate using
Use slab mode when you know the length, width and thickness of a rectangular pour.
LIVE PREVIEWSlab / pad
Calculated10 ft × 10 ft4 in thick · 1 item
Illustrative geometry only — use the entered dimensions for ordering.ORDER VOLUME
—yd³
Concrete including the selected extra-material allowance.
Base volume—yd³ before extra
Extra volume—yd³ allowance
Metric volume—m³ to order
Project area—ft²
MULTIPLE POURS
Build one combined concrete order.
Add the current calculation to a temporary project list, then mix slabs, footings, post holes, known areas and known volumes into one combined total. The selected extra percentage is applied once to the combined base volume.
No pours added yet. Calculate a slab, footing, post-hole group or known quantity above, then add it here.
Pour items0combined calculations
Base concrete—yd³ before extra
Project order total—yd³ including extra
PURCHASE PLANNING
Ready-mix or bagged concrete?
Turn either the current calculation or your combined project total into a purchase quantity. Use ready-mix for a volume-based quote or compare standard 40 lb, 60 lb and 80 lb bags for smaller jobs.
Purchase plan uses
Enter a supplier price only if you have one. Unit switching converts the price basis so the estimated total stays the same.
Bag counts always round up to whole bags. Yield values are planning estimates; confirm the product label before buying.
PURCHASE QUANTITY—Ready-mix concrete
Estimated material costAdd a priceOptional supplier pricing
BAG ALTERNATIVES
Includes the selected extra-material allowance.Equivalent whole-bag quantities
PROJECT OUTPUT
Concrete order summary.
A compact view of the calculation currently feeding Purchase Planning. Copy it to your notes or print the clean summary to save it as a PDF for a supplier quote or project record.
ScopeCurrent calculationSlab
Base concrete—yd³ before extra
Order concrete—yd³ including extra
Allowance10%applied once to the base volume
POUR BREAKDOWN
Current calculation
SHOPPING OUTPUT
What to ask for
Ready-mix concrete—Current calculation
Estimated material costAdd a priceOptional supplier pricing
Whole-bag reference—40 lb · 60 lb · 80 lb alternatives
Planning estimate only. Confirm mix specification, minimum delivery, short-load fees, bag yield and supplier requirements before ordering.
HOW IT WORKS
Start with the measurements you already know.
Slab and footing modes calculate rectangular volumes, while post-hole mode uses cylindrical geometry. Known area and known volume cover projects where part of the calculation is already available. Identical-item quantities and the multiple-pour list let one order represent a complete job without duplicating the core maths.
Base volume = Length × Width × Thickness
Order volume = Base volume × (1 + Extra %)
Order volume = Base volume × (1 + Extra %)
FIVE INPUT PATHS
Use the geometry that matches each pour.
Rectangular slabs, pads and patios. Quantity can represent several identical pours.
Continuous or repeated rectangular footings using length, width, depth and quantity.
Cylindrical holes using diameter, depth and number of holes.
Square footage or square meters plus the concrete thickness.
A cubic-yard or cubic-meter figure that only needs an ordering allowance.