Case 1
- Density of the material
- 1000kg/m³
- Local gravitational acceleration
- 9.80665m/s²
9,806.65N/m³
Open with these valuesSpecific Weight Calculator
9,806.65N/m³
Result: 9,806.65 N/m³Specific weight is density times gravity: fresh water at 1000 kg/m³ weighs 9806.65 N per cubic metre on Earth. Unlike density it changes with location — the same water is only 1620 N/m³ on the Moon. Do not confuse it with specific gravity, which is a dimensionless ratio and carries no g.
The numbers at a glance
Held fixed: Density of the material 1,000.000 kg/m³.
| Local gravitational acceleration (m/s²) | Result (N/m³) |
|---|---|
| 2.50000 | 2,500.00 |
| 5.00000 | 5,000.00 |
| 7.50000 | 7,500.00 |
| 9.80665Your value | 9,806.65 |
| 10.00000 | 10,000.00 |
| 12.50000 | 12,500.00 |
| 15.00000 | 15,000.00 |
| 17.50000 | 17,500.00 |
Worked examples
Case 2
- Density of the material
- 2700kg/m³
- Local gravitational acceleration
- 9.80665m/s²
26,477.95N/m³
Open with these valuesCase 3
- Density of the material
- 1000kg/m³
- Local gravitational acceleration
- 1.62m/s²
1,620.00N/m³
Open with these valuesHow it's calculated
γ = ρ × g
- StepEnter the mass density in kilograms per cubic metre.
- StepLeave gravity at 9.80665 m/s² for Earth, or enter the local value.
- ResultRead the weight density in newtons per cubic metre.
Reference table
| Density, gravity | Material and place | γ (N/m³) |
|---|---|---|
| 1000, 1.62 | Fresh water on the Moon | 1620 |
| 789, 9.80665 | Ethanol on Earth | 7737.44685 |
| 1000, 9.80665 | Fresh water on Earth | 9806.65 |
| 2700, 9.80665 | Aluminium on Earth | 26477.955 |
| 13534, 9.80665 | Mercury on Earth | 132723.2011 |
Questions
How do I calculate specific weight?
Multiply the density by the local gravitational acceleration: γ = ρ × g. Use kilograms per cubic metre and metres per second squared to get newtons per cubic metre. Fresh water at 1000 kg/m³ on Earth gives 9806.65 N/m³.
What is specific weight?
Specific weight, also called weight density, is the weight of a material per unit of volume. It says how heavy a cubic metre of a substance is under gravity, in newtons per cubic metre. Engineers use it for hydrostatic pressure, buoyancy and structural loads.
What is the difference between specific weight and density?
Density is mass per unit volume in kg/m³ and does not depend on gravity. Specific weight is weight per unit volume in N/m³ and equals density times gravity. The same material has the same density everywhere but a smaller specific weight where gravity is weaker.
Is specific weight the same as specific gravity?
No. Specific gravity is a dimensionless ratio comparing a material's density to that of water, so it has no units. Specific weight is a physical quantity in N/m³ that gives the actual weight per cubic metre.
Does specific weight change with gravity?
Yes, in direct proportion. Water has a specific weight of about 9806.65 N/m³ on Earth but only around 1620 N/m³ on the Moon, even though its density stays at 1000 kg/m³.
Sources and last check
Information, not professional advice.