The concrete calculator estimates volume for rectangular slabs, rectangular columns, and cylinders in cubic meters. It also converts the result to liters and applies an optional waste allowance for ordering planning.
How to use this calculator
For rectangular shapes, enter length, width, and depth or height in meters. For a cylinder, enter diameter in the length field and height in depth; width is ignored. Add a waste percentage if desired.
Formula & calculation method
Rectangular volume = length × width × height; cylinder volume = π × (diameter/2)² × heightNet volume is multiplied by one plus the waste rate. One cubic meter equals 1,000 liters. All dimensions must be in meters so the resulting volume remains in cubic meters.
Worked example
A slab measuring 4 by 3 meters with 0.15-meter depth has a net volume of 1.8 m³. A 5% allowance increases the planning quantity to 1.89 m³.
Why this is useful
The calculator provides both geometric volume and an adjusted order estimate. Separate net and allowance results make it easier to understand how much extra material was included.
Limitations to keep in mind
Actual requirements vary with excavation, uneven subgrades, formwork, spillage, compaction, and measurement accuracy. This is a material-volume estimate only, not structural design or reinforcement advice.
Frequently asked questions
Does cylinder mode use diameter or radius?
Use the full diameter in the length field. The calculator divides it by two to obtain the radius.
Is waste included in net volume?
No. Net geometric volume and adjusted volume are shown separately so the allowance remains clear.
Does this calculate concrete weight or bags?
No. Those require mix density or bag yield. Use the supplier's product data to convert volume into bag quantities.