Mass Calculator
Find mass from density and volume (m = ρ × V), with a comparison showing how that mass would weigh on Earth, the Moon, and other planets.
Mass
2000 kg
A density of 1000 kg/m³ times a volume of 2 m³ gives a mass of 2000 kg (4409.2452 lb).
Mass (grams)
2000000 g
Mass (pounds)
4409.2452 lb
Density Used
1000 kg/m³
Volume Used
2 m³
Mass vs. Weight — What's the Difference?
Mass is the amount of matter in an object — a fundamental, unchanging property measured in kilograms or pounds-mass. Weight, by contrast, is the force gravity exerts on that mass, and it changes depending on where you are: a 70 kg person's mass stays exactly 70 kg everywhere in the universe, but their weight on the Moon would be only about one-sixth of their weight on Earth, since the Moon's gravity is much weaker.
This calculator finds mass from density and volume (m = ρ × V, a rearrangement of the density formula), then shows the equivalent weight force at various gravitational accelerations so you can see how the same mass would "feel" on different planets.
Equivalent Weight Across the Solar System
How your calculated mass would weigh under different gravitational accelerations.
| Location | Gravity (m/s²) | Weight Force (N) | Equivalent Weight (lb) |
|---|---|---|---|
| Mercury | 3.70 | 7,400.0 N | 1663.53 lb |
| Venus | 8.87 | 17,740.0 N | 3987.97 lb |
| Earth | 9.807 | 19,614.0 N | 4409.25 lb |
| Moon | 1.62 | 3,240.0 N | 728.36 lb |
| Mars | 3.71 | 7,420.0 N | 1668.02 lb |
| Jupiter | 24.79 | 49,580.0 N | 11145.63 lb |
| Saturn | 10.44 | 20,880.0 N | 4693.84 lb |
How Is Mass Calculated?
Mass is found by rearranging the density formula (density = mass ÷ volume) to solve for mass directly: multiply a material's density by the volume you have of it.
Why Astronauts Feel "Weightless" But Aren't Massless
Astronauts in orbit are in continuous freefall around Earth, which produces a sensation of weightlessness — but their mass never changes. If you could measure their mass with a device that doesn't rely on gravity (like an inertial balance), it would read exactly the same in orbit as on the ground.
Kilograms vs. Pounds: A Common Mix-Up
In everyday US usage, "pounds" almost always refers to weight (a force), while the kilogram is officially a unit of mass. This calculator reports "pound" values as the Earth-standard mass equivalent (1 kg ≈ 2.205 lb) for the main result, and as true gravity-adjusted force-equivalents in the planetary weight table.
Density Determines How "Heavy" Something Feels for Its Size
Two objects of identical volume can have wildly different masses depending on density — a liter of water has a mass of 1 kg, while a liter of lead has a mass of over 11 kg, which is why density is such a useful material property for identifying substances.
Example — Your Current Inputs
A density of 1000 kg/m³ times a volume of 2 m³ gives a mass of 2000 kg (4409.2452 lb).
Additional Example — A Gold Bar
A standard gold bar with a volume of about 0.0052 m³ (a common 400 troy ounce / 12.4 kg good delivery bar shape) and gold's density of 19,300 kg/m³ has a mass of about 100 kg — which would weigh roughly 981 N on Earth but only about 162 N on the Moon.
About These Parameters
- Density
- The mass per unit volume of the material — water is 1,000 kg/m³ (1 g/cm³), a useful reference point since most everyday materials range from less dense (wood, ice) to far denser (metals).
- Volume
- The amount of space the material occupies, in your choice of common volume units — converted internally to cubic meters for the calculation.
Frequently Asked Questions
Is mass the same as weight?
No — mass measures the amount of matter in an object and never changes. Weight is the force gravity exerts on that mass, and it varies depending on the local gravitational acceleration.
Why does the Moon have less gravity than Earth?
Gravitational acceleration depends on a body's mass and radius. The Moon has far less mass than Earth, producing roughly one-sixth the surface gravity even though its radius is also smaller than Earth's.
How do I find density if I only know mass and volume?
Divide mass by volume (density = mass ÷ volume) — see the Density Calculator for a dedicated tool that solves for any of mass, volume, or density from the other two.