Mass Calculator
Calculate Mass from Density & Volume, Convert Units & Calculate Weight
📏 Pro Tips for Mass Calculations:
Mass and weight are different - mass constant, weight changes by location. Always use SI units (kg) for scientific accuracy. Density must match volume units. Multiple calculator modes for different needs. Remember: W = m × g where g depends on location.
Calculate Mass from Density and Volume
✅ Mass Calculation Results:
Convert Between Mass and Weight
✅ Mass-Weight Calculation Results:
Mass Unit Converter
Conversion Reference Table:
| Unit | Symbol | Equivalent (kg) | Category |
|---|---|---|---|
| Kilogram | kg | 1 | SI Unit |
| Gram | g | 0.001 | Metric |
| Milligram | mg | 0.000001 | Metric |
| Microgram | µg | 0.000000001 | Metric |
| Metric Ton | t | 1000 | Metric |
| Pound | lb | 0.453592 | Imperial |
| Ounce | oz | 0.0283495 | Imperial |
| Stone | st | 6.35029 | Imperial |
| US Ton | ton | 907.185 | US Custom |
✅ Unit Conversion Results:
Mass Concepts & Understanding
What is Mass?
Mass is fundamental property of matter representing amount of substance in an object. Measured in kilograms (kg) in SI system. Constant regardless of location - same mass on Earth, Moon, or Mars. Different from weight which depends on gravity.
Mass vs Weight
| Property | Mass | Weight |
|---|---|---|
| Definition | Amount of matter | Gravitational force |
| Unit | Kilogram (kg) | Newton (N) |
| Changes with location? | No (constant) | Yes (varies) |
| Measured with | Balance scale | Spring scale |
| Example | 70 kg person always 70 kg | 70 kg person weighs ~686 N on Earth |
| In space | 70 kg (unchanged) | 0 N (weightless) |
Types of Mass
- Inertial Mass: Resistance to acceleration (F = m × a). How hard to push object. Same magnitude everywhere.
- Gravitational Mass: Response to gravity (W = m × g). How strongly gravity attracts. Equivalent to inertial mass.
- Rest Mass: Intrinsic mass of object at rest. Used in relativity equations. Doesn't change with velocity.
Gravitational Acceleration on Different Bodies
| Location | g Value (m/s²) | Weight on Moon vs Earth |
|---|---|---|
| Earth | 9.8 | Reference (100%) |
| Moon | 1.62 | ~17% of Earth |
| Mars | 3.71 | ~38% of Earth |
| Jupiter | 24.79 | ~253% of Earth |
| Mercury | 3.7 | ~38% of Earth |
| Venus | 8.87 | ~91% of Earth |
Key Points to Remember:
- Mass: intrinsic property, never changes
- Weight: depends on gravity, changes by location
- Astronauts in orbit: mass unchanged, weight = 0
- Formula: W = m × g (where g varies)
- SI units: mass in kg, weight in N
📚 Understanding Mass in Physics
What is Mass?:
Mass is fundamental property of matter that quantifies amount of substance in object. In classical physics, mass appears in two contexts: inertial mass (resistance to acceleration) and gravitational mass (response to gravity). Both measured as equivalent. SI standard unit is kilogram (kg). Mass is invariant - doesn't change with location, velocity, or environmental conditions.
Measurement Methods:- Balance Scale: Compares unknown mass to standard masses. Works anywhere (no gravity needed). Most accurate traditional method.
- Spring Scale: Measures weight (force). Requires gravity. Different reading on different planets same mass.
- Analytical Balance: Digital precision. ±0.0001 g typical. Electronic measurement of mass.
- Calculation: From density and volume: m = ρ × V. From weight: m = W / g
- Misconception: Heavier objects fall faster. Truth: All objects fall at same rate (in vacuum).
- Misconception: Astronauts are weightless have no mass. Truth: They have same mass, zero weight (no gravity).
- Misconception: Mass and weight are same thing. Truth: Mass constant, weight changes with gravity.
❓ Frequently Asked Questions
How much does a 70 kg person weigh on different planets?
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Using W = m × g: Earth (9.8 m/s²) = 686 N. Moon (1.62 m/s²) = 113 N. Mars (3.71 m/s²) = 260 N. Jupiter (24.79 m/s²) = 1735 N. Mass stays 70 kg everywhere, but weight varies dramatically with local g value.
Why is mass measured in kilograms but weight in newtons?
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Mass measures amount of matter (kg). Weight measures gravitational force (Newtons). Different physical quantities require different units. Confusion arises because weight commonly measured in "pounds" in everyday use, but scientifically weight = force in Newtons.
Can density and mass calculations work in space?
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Yes! m = ρ × V formula works anywhere. Density and volume unchanged by location. Calculated mass same in space as on Earth. Weight calculation (W = m × g) different: in space g ≈ 0, so weight ≈ 0, but mass unchanged.
What's the difference between pound (lb) and pound-force (lbf)?
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Pound (lb) or pound-mass: unit of mass. Pound-force (lbf): unit of weight/force. On Earth: 1 pound-mass weighs 1 pound-force. In SI: 1 lb-mass = 0.454 kg, 1 lbf = 4.45 N. Different units cause confusion in imperial system.
How do scales work if weight changes but mass doesn't?
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Spring scales measure force (weight). Calibrated at specific gravity (usually Earth). Same mass produces less force on Moon - spring compresses less, showing lower reading. Balance scales compare masses directly - don't depend on gravity. Same mass balances on Earth and Moon.
What is proper usage of metric ton vs US ton?
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Metric ton (tonne): 1000 kg, used internationally/scientifically. US short ton: 2000 pounds = 907.185 kg. UK long ton: 2240 pounds = 1016.05 kg. Always clarify which ton used. Science uses metric tons exclusively.
Why do astronauts appear weightless in orbit?
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Astronauts in orbit aren't in zero gravity - they're in continuous free fall around Earth. Both astronauts and spacecraft falling at same rate - no relative force. Gravity still acts (prevents escape), but weightlessness results from free-fall, not gravity absence. Mass unchanged.
How does Einstein's mass-energy equivalence affect calculations?
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Formula E = mc². Very small mass converts to enormous energy. In everyday life: negligible effect. At particle accelerator speeds: significant. For basic calculations: use classical physics (m = ρ × V). Relativistic effects only relevant at extreme velocities/energies.