m3 to kg depends on density. For a quick check: 1 m³ of water is about 1000 kg, normal concrete is about 2400 kg, and dry sand is often around 1600 kg. Pick a material or enter your own density below.
1. Enter volume
1. Enter mass (weight)
2. Choose material (or set density)
1 m³ of Water (1000 kg/m³)
=
density ρ = 1000 kg/m³
3. Result in all units — click to copy
Formula
m = V × ρ — mass equals volume times density.Example: 1 m³ of concrete (ρ = 2400 kg/m³) → m = 1 × 2400 = 2400 kg.
Quick reference: 1 m³ of common materials
| Material | kg | t | lb | US ton |
|---|
FAQ
How do I convert m³ to kg?
Multiply the volume in cubic meters by the density of the material in kg/m³.
The formula is m = V × ρ. For example, 1 m³ of water
(ρ = 1000 kg/m³) weighs 1000 kg, while 1 m³ of concrete
(ρ = 2400 kg/m³) weighs 2400 kg.
How do I convert kg to m³?
Divide the mass in kilograms by the density in kg/m³: V = m / ρ.
For example, 5000 kg of sand (ρ = 1600 kg/m³) takes up 5000 / 1600 ≈ 3.125 m³.
Switch to the kg → m³ tab to do this directly.
Why does the same volume give different weights?
Because materials have different densities. A cubic meter of feathers, water, sand and
steel all have very different masses even though the volume is the same. Density (ρ)
is the bridge between volume and mass — that is why this calculator asks you to
select a material first.
What does 1 m³ of concrete weigh?
Normal-weight concrete is usually taken as 2400 kg/m³ (2.4 t or about 5291 lb per
cubic meter). Reinforced concrete is heavier — about 2500 kg/m³ (2.5 t).
Lightweight structural concrete ranges from 1600 to 1900 kg/m³.
How do I convert lb/ft³ to kg/m³?
Multiply lb/ft³ by 16.0185 to get kg/m³. So a material listed at
150 lb/ft³ has a density of about 2403 kg/m³. The reverse factor is
1 kg/m³ ≈ 0.06243 lb/ft³.
Can I enter my own density value?
Yes. If your material is not in the list, choose «— custom —» from the dropdown
and type the density directly into the «Density (kg/m³)» field. The result
updates instantly.
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m3 to kg formula
Mass in kg = volume in m³ × density in kg/m³. The reverse is volume in m³ = mass in kg ÷ density. This is why cubic meters cannot be converted to kilograms without a material or density value.
Common examples
Use water for liquid volume checks, concrete for building quantities, and custom density for soil, stone, metal, fuel or any material from a datasheet. The calculator also handles the reverse kg to m³ case on the same page.