Density,
mass, volume
— solved.

Density reference: tables & conversions.

Density is mass over volume, but a usable answer needs reference values and clean unit conversions — and those are what this page collects. Below are the densities of common solids, liquids at 20 °C, and gases at standard temperature and pressure, the conversion factors between metric and customary units, and the specific gravity scale that decides whether a sample floats in fresh water.

Densities of common solids at 20 °C, 1 atm

Values from the CRC Handbook of Chemistry and Physics, 102nd edition, with wood ranges drawn from the USDA Wood Handbook (FPL-GTR-190). Click any material card above to pre-fill the calculator with that density.

Common liquids at 20 °C

Pure water reaches its peak density of 1000 kg/m³ at 3.98 °C, then loses about 0.02% per degree as it warms. The 20 °C row below is the standard laboratory reference.

Common gases at STP (0 °C, 1 atm)

Gas density tracks the ideal gas law: ρ = (P·M) / (R·T), where M is molar mass in kg/mol and R is 8.31446 J/(mol·K). Doubling pressure doubles density; doubling absolute temperature halves it.

Density unit conversion factors

To convert a value in the left column into the right column, multiply by the factor shown. The calculator above performs these conversions internally; the table is for hand checks and crossing between drawings or spec sheets.

Mass unit conversion factors

Volume unit conversion factors

A US fluid ounce is 29.5735 mL and a UK fluid ounce is 28.4131 mL. They share a name and a symbol but resolve to different volumes; the calculator above keeps the two as separate units to prevent silent miscalculations.

Specific gravity scale and buoyancy threshold

Specific gravity (SG) divides a substance's density by the density of pure water at 4 °C (1000 kg/m³). The result is dimensionless, which is why pycnometer measurements and hydrometer readings are usually quoted as SG rather than absolute density. The float-or-sink threshold sits at SG = 1.000. Anything below floats in fresh water; anything above sinks.

Density formula and worked example

The three forms of the relation:

Worked example. A graduated cylinder reads 250 mL of olive oil. The combined cylinder and oil mass on a balance is 480.5 g; the empty cylinder is 251.0 g.

Convert to SI: 0.918 g/cm³ × 1000 = 918 kg/m³. Convert to imperial: 0.918 × 62.428 = 57.3 lb/ft³. Compare to the liquid table above: olive oil reference is 0.918 g/cm³, agreement to three decimal places. The buoyancy indicator compares 918 kg/m³ against 1000 kg/m³ and returns “floats in water” because the sample is less dense than the reference fluid.

Solving for mass, volume, or density

Density is mass per unit volume — the mass of a substance divided by the volume it occupies, written D = M / V. Because that identity rearranges three ways, the same calculator answers a mass to volume conversion, a mass from density and volume lookup, or a density to volume calculation. Enter the two values you have and the field you leave blank is the one Massvo solves. The worked rows below show each rearrangement explicitly.

Mass to volume. To convert mass to volume you divide by density: V = M / D. Take 500 g of olive oil at 0.918 g/cm³. Then V = 500 / 0.918 = 544.7 cm³, which is 0.5447 L. Keep mass and density in compatible units (grams with g/cm³, or kilograms with kg/m³) and the volume falls out in the matching cube unit.

Mass from density and volume. Going the other way, mass is density times volume: M = D × V. A 200 cm³ block of aluminum at 2.700 g/cm³ has mass M = 2.700 × 200 = 540 g. This is the rearrangement a “mass from density and volume calculator” performs — it is the same D = M / V identity solved for M.

Density to volume. Given a mass and a density, volume is again V = M / D. One kilogram of iron at 7874 kg/m³ occupies V = 1.000 / 7874 = 1.270 × 10⁻⁴ m³, or 127.0 cm³. A material with a high mass per unit volume — a high density — packs that mass into a small volume, which is why a kilogram of iron is far smaller than a kilogram of cork. For the full editorial walk-through of mass, volume, and the SI redefinition, see /learn.

Worked mass to volume conversions, each using the same preset density the calculator loads for that material:

Densities in this table are the calculator's built-in presets. Handbook literature values in the solids and liquids tables above can differ for materials with natural spread, such as concrete, fuels, and wood. To go the other way and find mass from a volume, multiply instead: M = D × V.

Standards and primary sources

Related concepts

• Archimedes principle:Buoyant force equals weight of fluid displaced; underlies the float/sink behavior the indicator reports.
• Pycnometer measurement:A calibrated flask used to determine the density of liquids and finely divided solids by displacement.
• Thermal expansion coefficient:Liquids and solids change density with temperature; for water near 4 °C the coefficient is anomalously near zero, then turns positive.
• Ideal gas law:PV = nRT relates the four state variables for gases; combined with molar mass it gives the density values in the gas table above.
• Molar volume:At STP, one mole of any ideal gas occupies 22.414 L, which converts cleanly between mass and volume for gas-phase calculations.