Mass, Volume & Material Lookup
Last reviewed: May 2026
Calculate density from mass and volume, or solve for mass or volume when density is known. Density = mass ÷ volume — one of the most fundamental relationships in physics, chemistry, engineering, and materials science. This calculator also includes a reference table of common material densities.1
| Material | g/cm³ | kg/m³ | lb/ft³ |
|---|---|---|---|
| Air (sea level) | 0.001225 | 1.225 | 0.076 |
| Water | 1.00 | 1,000 | 62.4 |
| Concrete | 2.40 | 2,400 | 150 |
| Aluminum | 2.70 | 2,700 | 169 |
| Steel | 7.85 | 7,850 | 490 |
| Copper | 8.96 | 8,960 | 559 |
| Gold | 19.3 | 19,300 | 1,204 |
Density is mass per unit volume: ρ = m/V. Water's density — 1 g/cm³ or 1,000 kg/m³ — is the reference point for everyday comparisons. Objects denser than water sink; less dense objects float. This simple principle explains why steel ships float (they enclose air, making their average density less than water), why oil spills spread across water surfaces (oil is 0.8-0.95 g/cm³), and why hot air balloons rise (heated air is less dense than surrounding cooler air).
Gases (at sea level): Air: 1.225 kg/m³, Helium: 0.164 kg/m³ (why it floats), CO₂: 1.977 kg/m³ (why it sinks and pools in low areas). Liquids: Water: 1,000 kg/m³, Gasoline: 720 kg/m³, Mercury: 13,546 kg/m³, Milk: 1,030 kg/m³. Solids: Ice: 917 kg/m³ (9% less than water — why ice floats), Aluminum: 2,700 kg/m³, Steel: 7,800 kg/m³, Gold: 19,300 kg/m³, Lead: 11,340 kg/m³, Oak wood: 600-900 kg/m³, Concrete: 2,300 kg/m³.
Material identification: Measuring an unknown object's mass and volume to calculate density can identify the material. A ring with density 19.3 g/cm³ is likely gold; at 10.5 g/cm³, it's probably silver. Archimedes famously used this principle to detect a fraudulent gold crown. Shipping and logistics: Packages are charged by dimensional weight or actual weight, whichever is greater — a box of feathers (low density) is charged for its volume, while a box of lead (high density) is charged for its weight. Cooking: Density determines whether ingredients layer or mix — cocktails with layered liquors exploit density differences between spirits with different sugar contents.
Density changes with temperature and pressure. Most substances become less dense (expand) when heated. Water is anomalous — it's densest at 4°C (39.2°F), not at freezing. This is why lakes freeze from the top down (surface water cools below 4°C, becomes less dense, and stays on top), allowing aquatic life to survive winter beneath the ice. Gases are highly compressible — air density drops from 1.225 kg/m³ at sea level to 0.414 kg/m³ at 30,000 feet altitude. This thinning explains why aircraft cabins must be pressurized and why high-altitude cooking requires adjustments.
Density (ρ) equals mass divided by volume, expressed in units like kg/m³, g/cm³, or lb/ft³. Water's density of 1.00 g/cm³ (1,000 kg/m³, 62.4 lb/ft³) serves as the universal reference point: materials denser than water sink; less dense materials float. Knowing density values enables practical calculations throughout engineering and daily life. Concrete at 2,400 kg/m³ means a 4-inch slab covering 1,000 sq ft weighs approximately 30,000 kg (66,000 lbs) — critical information for foundation design. Gasoline at 0.75 g/cm³ is 25% lighter than water, which is why fuel floats on water during spills. Air at sea level has a density of about 1.225 kg/m³ — seemingly negligible until you calculate that a typical house contains roughly 200-300 kg of air. The density of cooking oil (0.91-0.93 g/cm³) being close to water's explains why oil floats and why vinaigrettes separate.
Density serves as a fingerprint for material identification. Pure gold has a density of 19.32 g/cm³ — significantly higher than common counterfeit materials like lead (11.34 g/cm³) or tungsten (19.25 g/cm³, the closest match). Archimedes legendarily used density to detect fraud in a golden crown: by measuring water displacement, he determined the crown contained silver (10.49 g/cm³) mixed with gold. Modern jewelers still use density testing — weighing an item in air then in water and applying the formula: density = weight_in_air ÷ (weight_in_air - weight_in_water) × density_of_water. Quality control in manufacturing uses density to detect voids, porosity, or contamination: a plastic part with density 5% below specification may contain air bubbles that weaken it. Petroleum products are graded by API gravity (a density-derived scale where lighter oils have higher API numbers), with crude oil ranging from heavy (API < 22.3, sinks in water) to light (API > 31.1).
Specific gravity (SG) is the ratio of a material's density to water's density — a dimensionless number that makes comparison intuitive. SG of 2.65 (quartz sand) means sand is 2.65 times denser than water. Because water's density in g/cm³ is 1.00, specific gravity numerically equals density in g/cm³ — but without units. Hydrometers measure specific gravity directly for liquids: winemakers use them to track fermentation (grape juice SG ~1.080 drops to ~0.990 as sugar converts to alcohol), brewers measure original and final gravity to calculate alcohol content (ABV ≈ (OG - FG) × 131.25), and battery technicians check electrolyte SG (fully charged = 1.265, discharged = 1.100). Urinalysis uses SG as a hydration marker: normal urine ranges from 1.005 to 1.030, with values below 1.005 indicating overhydration and above 1.030 suggesting dehydration.
Archimedes' principle states that an object immersed in fluid experiences an upward force equal to the weight of fluid displaced. An object floats when its average density is less than the fluid's density. Ships are made of steel (density 7.85 g/cm³, far denser than water) but float because their hull shape encloses a large volume of air, making the average density of the ship-plus-air system less than 1.0 g/cm³. Naval architects calculate displacement tonnage — the mass of water a ship displaces when floating at its design waterline — to determine cargo capacity. A ship displacing 50,000 tons of seawater (density 1.025 g/cm³) has a total mass of 50,000 tons, and the difference between its empty displacement and full displacement equals its cargo capacity. The Dead Sea (SG 1.24 due to dissolved salts) makes the human body (average SG ~1.01) noticeably more buoyant — you float effortlessly because the density difference is much larger than in fresh water.
Density (ρ) equals mass divided by volume, expressed in units like kg/m³, g/cm³, or lb/ft³. Water's density of 1.00 g/cm³ (1,000 kg/m³, 62.4 lb/ft³) serves as the universal reference point: materials denser than water sink; less dense materials float. Knowing density values enables practical calculations throughout engineering and daily life. Concrete at 2,400 kg/m³ means a 4-inch slab covering 1,000 sq ft weighs approximately 30,000 kg (66,000 lbs) — critical information for foundation design. Gasoline at 0.75 g/cm³ is 25% lighter than water, which is why fuel floats on water during spills. Air at sea level has a density of about 1.225 kg/m³ — seemingly negligible until you calculate that a typical house contains roughly 200-300 kg of air. The density of cooking oil (0.91-0.93 g/cm³) being close to water's explains why oil floats and why vinaigrettes separate.
Density serves as a fingerprint for material identification. Pure gold has a density of 19.32 g/cm³ — significantly higher than common counterfeit materials like lead (11.34 g/cm³) or tungsten (19.25 g/cm³, the closest match). Archimedes legendarily used density to detect fraud in a golden crown: by measuring water displacement, he determined the crown contained silver (10.49 g/cm³) mixed with gold. Modern jewelers still use density testing — weighing an item in air then in water and applying the formula: density = weight_in_air ÷ (weight_in_air - weight_in_water) × density_of_water. Quality control in manufacturing uses density to detect voids, porosity, or contamination: a plastic part with density 5% below specification may contain air bubbles that weaken it. Petroleum products are graded by API gravity (a density-derived scale where lighter oils have higher API numbers), with crude oil ranging from heavy (API < 22.3, sinks in water) to light (API > 31.1).
Specific gravity (SG) is the ratio of a material's density to water's density — a dimensionless number that makes comparison intuitive. SG of 2.65 (quartz sand) means sand is 2.65 times denser than water. Because water's density in g/cm³ is 1.00, specific gravity numerically equals density in g/cm³ — but without units. Hydrometers measure specific gravity directly for liquids: winemakers use them to track fermentation (grape juice SG ~1.080 drops to ~0.990 as sugar converts to alcohol), brewers measure original and final gravity to calculate alcohol content (ABV ≈ (OG - FG) × 131.25), and battery technicians check electrolyte SG (fully charged = 1.265, discharged = 1.100). Urinalysis uses SG as a hydration marker: normal urine ranges from 1.005 to 1.030, with values below 1.005 indicating overhydration and above 1.030 suggesting dehydration.
Archimedes' principle states that an object immersed in fluid experiences an upward force equal to the weight of fluid displaced. An object floats when its average density is less than the fluid's density. Ships are made of steel (density 7.85 g/cm³, far denser than water) but float because their hull shape encloses a large volume of air, making the average density of the ship-plus-air system less than 1.0 g/cm³. Naval architects calculate displacement tonnage — the mass of water a ship displaces when floating at its design waterline — to determine cargo capacity. A ship displacing 50,000 tons of seawater (density 1.025 g/cm³) has a total mass of 50,000 tons, and the difference between its empty displacement and full displacement equals its cargo capacity. The Dead Sea (SG 1.24 due to dissolved salts) makes the human body (average SG ~1.01) noticeably more buoyant — you float effortlessly because the density difference is much larger than in fresh water.
Density (ρ) equals mass divided by volume, expressed in units like kg/m³, g/cm³, or lb/ft³. Water's density of 1.00 g/cm³ (1,000 kg/m³, 62.4 lb/ft³) serves as the universal reference point: materials denser than water sink; less dense materials float. Knowing density values enables practical calculations throughout engineering and daily life. Concrete at 2,400 kg/m³ means a 4-inch slab covering 1,000 sq ft weighs approximately 30,000 kg (66,000 lbs) — critical information for foundation design. Gasoline at 0.75 g/cm³ is 25% lighter than water, which is why fuel floats on water during spills. Air at sea level has a density of about 1.225 kg/m³ — seemingly negligible until you calculate that a typical house contains roughly 200-300 kg of air. The density of cooking oil (0.91-0.93 g/cm³) being close to water's explains why oil floats and why vinaigrettes separate.
Density serves as a fingerprint for material identification. Pure gold has a density of 19.32 g/cm³ — significantly higher than common counterfeit materials like lead (11.34 g/cm³) or tungsten (19.25 g/cm³, the closest match). Archimedes legendarily used density to detect fraud in a golden crown: by measuring water displacement, he determined the crown contained silver (10.49 g/cm³) mixed with gold. Modern jewelers still use density testing — weighing an item in air then in water and applying the formula: density = weight_in_air ÷ (weight_in_air - weight_in_water) × density_of_water. Quality control in manufacturing uses density to detect voids, porosity, or contamination: a plastic part with density 5% below specification may contain air bubbles that weaken it. Petroleum products are graded by API gravity (a density-derived scale where lighter oils have higher API numbers), with crude oil ranging from heavy (API < 22.3, sinks in water) to light (API > 31.1).
Specific gravity (SG) is the ratio of a material's density to water's density — a dimensionless number that makes comparison intuitive. SG of 2.65 (quartz sand) means sand is 2.65 times denser than water. Because water's density in g/cm³ is 1.00, specific gravity numerically equals density in g/cm³ — but without units. Hydrometers measure specific gravity directly for liquids: winemakers use them to track fermentation (grape juice SG ~1.080 drops to ~0.990 as sugar converts to alcohol), brewers measure original and final gravity to calculate alcohol content (ABV ≈ (OG - FG) × 131.25), and battery technicians check electrolyte SG (fully charged = 1.265, discharged = 1.100). Urinalysis uses SG as a hydration marker: normal urine ranges from 1.005 to 1.030, with values below 1.005 indicating overhydration and above 1.030 suggesting dehydration.
Archimedes' principle states that an object immersed in fluid experiences an upward force equal to the weight of fluid displaced. An object floats when its average density is less than the fluid's density. Ships are made of steel (density 7.85 g/cm³, far denser than water) but float because their hull shape encloses a large volume of air, making the average density of the ship-plus-air system less than 1.0 g/cm³. Naval architects calculate displacement tonnage — the mass of water a ship displaces when floating at its design waterline — to determine cargo capacity. A ship displacing 50,000 tons of seawater (density 1.025 g/cm³) has a total mass of 50,000 tons, and the difference between its empty displacement and full displacement equals its cargo capacity. The Dead Sea (SG 1.24 due to dissolved salts) makes the human body (average SG ~1.01) noticeably more buoyant — you float effortlessly because the density difference is much larger than in fresh water.
Density (ρ) equals mass divided by volume, expressed in units like kg/m³, g/cm³, or lb/ft³. Water's density of 1.00 g/cm³ (1,000 kg/m³, 62.4 lb/ft³) serves as the universal reference point: materials denser than water sink; less dense materials float. Knowing density values enables practical calculations throughout engineering and daily life. Concrete at 2,400 kg/m³ means a 4-inch slab covering 1,000 sq ft weighs approximately 30,000 kg (66,000 lbs) — critical information for foundation design. Gasoline at 0.75 g/cm³ is 25% lighter than water, which is why fuel floats on water during spills. Air at sea level has a density of about 1.225 kg/m³ — seemingly negligible until you calculate that a typical house contains roughly 200-300 kg of air. The density of cooking oil (0.91-0.93 g/cm³) being close to water's explains why oil floats and why vinaigrettes separate.
Density serves as a fingerprint for material identification. Pure gold has a density of 19.32 g/cm³ — significantly higher than common counterfeit materials like lead (11.34 g/cm³) or tungsten (19.25 g/cm³, the closest match). Archimedes legendarily used density to detect fraud in a golden crown: by measuring water displacement, he determined the crown contained silver (10.49 g/cm³) mixed with gold. Modern jewelers still use density testing — weighing an item in air then in water and applying the formula: density = weight_in_air ÷ (weight_in_air - weight_in_water) × density_of_water. Quality control in manufacturing uses density to detect voids, porosity, or contamination: a plastic part with density 5% below specification may contain air bubbles that weaken it. Petroleum products are graded by API gravity (a density-derived scale where lighter oils have higher API numbers), with crude oil ranging from heavy (API < 22.3, sinks in water) to light (API > 31.1).
Specific gravity (SG) is the ratio of a material's density to water's density — a dimensionless number that makes comparison intuitive. SG of 2.65 (quartz sand) means sand is 2.65 times denser than water. Because water's density in g/cm³ is 1.00, specific gravity numerically equals density in g/cm³ — but without units. Hydrometers measure specific gravity directly for liquids: winemakers use them to track fermentation (grape juice SG ~1.080 drops to ~0.990 as sugar converts to alcohol), brewers measure original and final gravity to calculate alcohol content (ABV ≈ (OG - FG) × 131.25), and battery technicians check electrolyte SG (fully charged = 1.265, discharged = 1.100). Urinalysis uses SG as a hydration marker: normal urine ranges from 1.005 to 1.030, with values below 1.005 indicating overhydration and above 1.030 suggesting dehydration.
Archimedes' principle states that an object immersed in fluid experiences an upward force equal to the weight of fluid displaced. An object floats when its average density is less than the fluid's density. Ships are made of steel (density 7.85 g/cm³, far denser than water) but float because their hull shape encloses a large volume of air, making the average density of the ship-plus-air system less than 1.0 g/cm³. Naval architects calculate displacement tonnage — the mass of water a ship displaces when floating at its design waterline — to determine cargo capacity. A ship displacing 50,000 tons of seawater (density 1.025 g/cm³) has a total mass of 50,000 tons, and the difference between its empty displacement and full displacement equals its cargo capacity. The Dead Sea (SG 1.24 due to dissolved salts) makes the human body (average SG ~1.01) noticeably more buoyant — you float effortlessly because the density difference is much larger than in fresh water.
Density (ρ) equals mass divided by volume, expressed in units like kg/m³, g/cm³, or lb/ft³. Water's density of 1.00 g/cm³ (1,000 kg/m³, 62.4 lb/ft³) serves as the universal reference point: materials denser than water sink; less dense materials float. Knowing density values enables practical calculations throughout engineering and daily life. Concrete at 2,400 kg/m³ means a 4-inch slab covering 1,000 sq ft weighs approximately 30,000 kg (66,000 lbs) — critical information for foundation design. Gasoline at 0.75 g/cm³ is 25% lighter than water, which is why fuel floats on water during spills. Air at sea level has a density of about 1.225 kg/m³ — seemingly negligible until you calculate that a typical house contains roughly 200-300 kg of air. The density of cooking oil (0.91-0.93 g/cm³) being close to water's explains why oil floats and why vinaigrettes separate.
Density serves as a fingerprint for material identification. Pure gold has a density of 19.32 g/cm³ — significantly higher than common counterfeit materials like lead (11.34 g/cm³) or tungsten (19.25 g/cm³, the closest match). Archimedes legendarily used density to detect fraud in a golden crown: by measuring water displacement, he determined the crown contained silver (10.49 g/cm³) mixed with gold. Modern jewelers still use density testing — weighing an item in air then in water and applying the formula: density = weight_in_air ÷ (weight_in_air - weight_in_water) × density_of_water. Quality control in manufacturing uses density to detect voids, porosity, or contamination: a plastic part with density 5% below specification may contain air bubbles that weaken it. Petroleum products are graded by API gravity (a density-derived scale where lighter oils have higher API numbers), with crude oil ranging from heavy (API < 22.3, sinks in water) to light (API > 31.1).
Specific gravity (SG) is the ratio of a material's density to water's density — a dimensionless number that makes comparison intuitive. SG of 2.65 (quartz sand) means sand is 2.65 times denser than water. Because water's density in g/cm³ is 1.00, specific gravity numerically equals density in g/cm³ — but without units. Hydrometers measure specific gravity directly for liquids: winemakers use them to track fermentation (grape juice SG ~1.080 drops to ~0.990 as sugar converts to alcohol), brewers measure original and final gravity to calculate alcohol content (ABV ≈ (OG - FG) × 131.25), and battery technicians check electrolyte SG (fully charged = 1.265, discharged = 1.100). Urinalysis uses SG as a hydration marker: normal urine ranges from 1.005 to 1.030, with values below 1.005 indicating overhydration and above 1.030 suggesting dehydration.
Archimedes' principle states that an object immersed in fluid experiences an upward force equal to the weight of fluid displaced. An object floats when its average density is less than the fluid's density. Ships are made of steel (density 7.85 g/cm³, far denser than water) but float because their hull shape encloses a large volume of air, making the average density of the ship-plus-air system less than 1.0 g/cm³. Naval architects calculate displacement tonnage — the mass of water a ship displaces when floating at its design waterline — to determine cargo capacity. A ship displacing 50,000 tons of seawater (density 1.025 g/cm³) has a total mass of 50,000 tons, and the difference between its empty displacement and full displacement equals its cargo capacity. The Dead Sea (SG 1.24 due to dissolved salts) makes the human body (average SG ~1.01) noticeably more buoyant — you float effortlessly because the density difference is much larger than in fresh water.
→ Water = 1 g/mL. The baseline for understanding all other densities.
→ Floats if < 1 g/mL. Anything less dense than water floats in it.
→ For construction: Density × volume = weight load for structural calculations.
→ Temperature matters. Density changes with temperature, especially for gases.
See also: Half-Life · Scientific · Weight · Volume