Density to Weight Calculator
Find the weight of any object: enter its density (kg/m³) and volume (m³), adjust gravitational acceleration if needed (Moon, Mars, etc.), and get the gravitational force in Newtons, kgf, and lbf.
kg/m³
m³
m/s²
W = ρ × V × g — the downward force exerted by gravity on the mass
- 1
Mass (m = ρ × V)
1,000 × 0.001 = 1Mass is density times volume; weight requires the additional gravity factor. - 2
Weight (W = m × g)
1 × 9.80665 = 9.81
How does this calculator work?
Weight = density × volume × gravity: W = ρ × V × g. For 0.001 m³ of water (ρ = 1 000 kg/m³) at standard Earth gravity (9.80665 m/s²), W = 1 000 × 0.001 × 9.80665 ≈ 9.81 N (≈ 1 kgf ≈ 2.2 lbf). Adjust g for the Moon (≈ 1.625) or Mars (≈ 3.72) to get off-Earth weights.
Formula
How this is calculated
Weight is not the same as mass. Mass (m) measures how much matter an object contains and is constant everywhere in the universe. Weight (W) is the gravitational force pulling the object downward — it depends on the local gravitational acceleration (g). The relationship is W = m × g. Since mass equals density times volume (m = ρ × V), the full formula for weight from density is W = ρ × V × g.
On Earth the standard gravitational acceleration is g = 9.80665 m/s² (a defined constant). At the Moon (g ≈ 1.625 m/s²) the same object weighs about one-sixth as much; on Mars (g ≈ 3.72 m/s²) about 38%. You can change g in the input to calculate weight on any celestial body.
Newtons (N) are the SI unit of force. Kilogram-force (kgf, sometimes called "kilopond") equals 9.80665 N and is widely used in engineering. Pound-force (lbf) is used in US customary and imperial systems (1 lbf ≈ 4.448 N). Note that colloquial "weight in kilograms" is actually mass — true weight in kgf equals mass in kg only at exactly g = 9.80665 m/s².
Frequently asked questions
Mass (kg) is the amount of matter; it is the same everywhere. Weight (N or kgf) is the gravitational force on that mass — it changes with local gravity. On the Moon your mass is the same as on Earth, but your weight is about one-sixth as large.
Divide Newtons by 9.80665 to get kgf: 98.07 N ÷ 9.80665 ≈ 10 kgf. Multiply Newtons by 0.2248 to get lbf: 100 N × 0.2248 ≈ 22.48 lbf.
g varies slightly with latitude, altitude, and local geology. The international standard value of 9.80665 m/s² is a defined constant used for metrology. At the equator g ≈ 9.78 m/s²; at the poles g ≈ 9.83 m/s².
Also known as
TG we-Calculate Editorial Team. (2026). Density to Weight Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/density-to-weight-calculator
TG we-Calculate Editorial Team. "Density to Weight Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/density-to-weight-calculator.
TG we-Calculate Editorial Team, "Density to Weight Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/density-to-weight-calculator
@misc{wecalculate_density_to_weight_calculator, title = {Density to Weight Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/density-to-weight-calculator}}, year = {2026}, note = {TG we-Calculate} }
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