How this calculator works
Mass is concrete volume multiplied by density. ACI describes normalweight concrete as approximately 2400 kg/m3; this is an estimate, not a specification for every mix. The lightweight value is an illustrative input within common ranges. Use a measured composite density for reinforced concrete, asphalt concrete or another aggregate blend rather than assuming a universal density from the material name. The word weight is used colloquially here for mass in kilograms or pounds.
Formula
Mass = volume x density; volume = mass / density; density = mass / volume.
Worked example
At 2400 kg/m3, 2.5 m3 concrete has a mass of 6000 kg. Conversely, a 1200 kg sample occupying 0.5 m3 has density 2400 kg/m3.
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Frequently asked questions
Does reinforcing steel change the estimate?
Yes. Either use a measured overall density or calculate steel and displaced concrete separately for an accurate composite mass.
Is wet concrete the same mass as dry bagged mix?
No. Water is added to the mix, and moisture changes with curing and drying. Bag mass is not the finished concrete density.
Can I use this for asphalt or unusual aggregates?
Yes, in custom-density mode. Obtain density from a material test or supplier because aggregate type and compaction can change it substantially.