Example: 2.5 m³ at an assumed 2,400 kg/m³
Mass = 2.5 × 2,400 = 6,000 kg = 6.000 metric tonnes. Dividing by 907.18474 gives approximately 6.614 US short tons. The physical quantity is identical; the unit has changed. This example excludes separately measured reinforcement and any loose-pile voids.
Get the right density for the question
Record whether you are measuring an intact element, fresh concrete or broken demolition material. The material's mass per solid cubic metre differs from the loose bulk density of a pile containing voids. Do not multiply a loose truck-bed volume by solid concrete density and treat the result as a reliable load weight.
Use the project's specified or measured density where available. The example's 2,400 kg/m³ is an explicit arithmetic input, not a guarantee for lightweight, heavyweight or every ordinary concrete mix. Document the source alongside the volume.
Keep metric tonnes separate from US short tons
In metric units, multiplying m³ by kg/m³ yields kilograms directly. Divide by 1,000 for tonnes, written t. A US short ton is 2,000 lb, approximately 907.18474 kg. Therefore the same physical mass has a numerically larger value in short tons than in metric tonnes.
The concrete-weight calculator displays its primary result in US tons and provides tonnes as a separate result. Read the unit label instead of copying only the number into a supplier quotation. Metric input does not make the word 'tons' automatically mean tonnes.
Measure additions and voids
A plain slab is length × width × thickness. Add thickened areas and separate elements only once; deduct intentional voids when the chosen volume model does not already remove them. For a composite element, reinforcement and other materials may need their own mass calculation depending on the purpose of the estimate.
If thickness varies, break the element into measured sections or use a documented geometric average that fits the shape. A large error in volume cannot be corrected by adding decimal places to density. Keep original measurements and rounding visible.
Mass is not a lifting or hauling approval
Use the calculation to understand an estimate, then obtain the verified mass and handling requirements needed for the actual operation. Truck payload, axle distribution, lifting points and equipment capacity are not decided by this calculator.
For demolition, obtain the haulier's usable capacity and the appropriate loose-material basis. Record the ticket unit and reconcile measured weights after collection. If a contractor quotes per tonne and another per cubic metre, first align both material condition and unit basis before comparing prices.
Do it in order
- Measure net solid volume and identify the material condition.
- Multiply by a documented density in matching units.
- Convert kilograms to the explicitly named mass unit and retain the assumptions.
Planning boundary
This is a mass estimate from stated inputs, not a certified handling, lifting or transport assessment.
Sources checked
Does one cubic metre always weigh 2.4 tonnes?
No. That follows only when the applicable density is 2,400 kg/m³. Use the specified or measured density for the actual material.
Can I price loose rubble with solid concrete density?
Not directly. Loose material includes voids, so use a suitable measured bulk density and the supplier's stated basis.