Home & Construction Calculators
Calculate the weight of fresh concrete for slabs, rectangular sections, round columns or a known volume. Results include pounds, kilograms and tons plus optional reinforcing steel.
Concrete weight formula
Cylinder volume = π × (diameter ÷ 2)² × height
Concrete weight = volume × density
Combined load = concrete + reinforcement
The calculator converts dimensions to cubic feet and cubic meters before applying density. One cubic yard equals 27 ft³. One cubic meter equals 35.3147 ft³.
Typical concrete density
Normal-weight fresh concrete is commonly estimated near 145–150 lb/ft³, or roughly 2,320–2,400 kg/m³. Lightweight and heavyweight mixes can differ significantly. Use the batch design or supplier value for load-critical work.
Worked example
A 20 ft × 10 ft slab that is 4 in thick has a volume of about 66.67 ft³, or 2.47 yd³. At 145 lb/ft³, the concrete weighs about 9,667 lb before reinforcing steel. With 2 lb of reinforcement per cubic foot, the combined estimated load is about 9,800 lb.
Why weight matters
- Planning truck payload and delivery access.
- Checking formwork and temporary support loads.
- Estimating demolition debris and disposal loads.
- Planning crane, hoist and lifting operations.
- Comparing normal, lightweight and specialty mixes.
Manual calculation steps
- Convert every linear dimension to the same unit.
- Calculate the geometric volume.
- Multiply by the number of identical sections.
- Add any volume allowance.
- Multiply volume by concrete density.
- Add reinforcing steel only when a combined load is needed.
- Divide the combined pounds by payload for an equivalent trip count.
Allowance affects volume and therefore weight. It can represent over-excavation, spillage or ordering contingency, but it should not replace accurate measurements.
Frequently asked questions
How much does one cubic yard of concrete weigh?
At 145–150 lb/ft³, one cubic yard weighs about 3,915–4,050 lb. The actual value depends on the mix.
Is dry concrete lighter than fresh concrete?
Yes, moisture changes over time, but design dead load and shipping weight should use the appropriate specified density rather than a guessed drying reduction.
Does this include rebar?
Concrete weight is shown separately. Enter a reinforcement rate to see an additional steel estimate and a combined load.
Can I calculate a round column?
Yes. Choose the cylinder option and enter diameter and height using the selected unit.
Common mistakes
- Treating inches as feet.
- Using cured or dry density for fresh delivery weight.
- Forgetting repeated sections.
- Confusing metric tonnes with US short tons.
- Ignoring vehicle and lifting safety margins.