What is the formula for finding mass from density?

Mass equals density multiplied by volume: m = rho x V. Density (rho) is mass per unit volume, so rearranging the density formula (rho = m / V) gives mass. The key is making sure your density and volume units are compatible before you multiply them, for example kg/m3 with m3, or g/cm3 with cm3.

How do I convert between density units like g/cm3 and kg/m3?

1 g/cm3 equals 1,000 kg/m3, because there are 1,000,000 cm3 in a cubic metre but only 1,000 grams in a kilogram (a factor of 1,000 difference). Similarly, 1 g/mL equals 1 g/cm3 equals 1 kg/L, since a millilitre and a cubic centimetre are the same volume. This calculator converts your chosen density and volume units automatically before multiplying them.

What is the density of common materials like water, steel or concrete?

Fresh water has a density of about 1,000 kg/m3 (1 g/cm3) at 4 degrees Celsius. Steel is around 7,850 kg/m3, aluminium is around 2,700 kg/m3, and standard concrete is around 2,400 kg/m3. Timber varies widely from around 400 to 800 kg/m3 depending on species and moisture content. Use the material preset in this calculator to load typical values, then adjust if you know the exact density of your material.

Density to Mass Calculator

This calculator works out the mass of an object, liquid or bulk material from its density and volume, using the formula mass = density x volume (m = rho V). It is useful for estimating weight before you have anything to weigh, such as ordering concrete, sand or timber, filling a tank or drum, or checking whether a load will overload a vehicle or lifting gear. Enter a density value and choose its unit (kg/m3, g/cm3, g/mL, kg/L or g/L), or pick a material preset such as water, seawater, steel, aluminium, concrete, timber, air or mercury to load a typical figure automatically. Then enter the volume, choose its unit (cubic metres, litres, millilitres or cubic centimetres), and pick whether the answer should show in kilograms, grams or tonnes. The calculator converts your density and volume into consistent SI units, multiplies them, and updates the mass instantly as you change any figure. Results include the headline mass, the converted density and volume in SI units, a step-by-step calculation breakdown, and the mass expressed in kilograms, grams, tonnes and pounds. Material presets are handy for quick estimates, but for engineering, trade or legal work use the manufacturer's or supplier's stated density instead, since real materials vary with moisture content, temperature and composition. Treat the result as an indicative estimate, not a certified figure.

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Verified formula Standard physics relationship: mass = density x volume (m = rho V). Material densities are typical reference values.

1. Density

Material preset (optional, loads typical density)

Density value

Density unit

2. Volume

Volume value

Volume unit

Show mass in

Mass Result

Mass
2,000 kg
1,000.00 kg/m3 x 2.0000 m3

Density (SI)

1,000.00

kg per cubic metre

Volume (SI)

2.0000

cubic metres

Calculation Breakdown

Density entered1,000.00 kg/m3

Density converted to kg/m31,000.00 kg/m3

Volume entered2.0000 m3

Volume converted to m32.000000 m3

Mass (kg)2,000.000 kg

Mass in Other Units

Kilograms (kg)2,000.000 kg

Grams (g)2,000,000.0 g

Tonnes (t)2.00000 t

Pounds (lb)4,409.240 lb

How to Calculate Mass from Density and Volume

Density describes how much mass is packed into a given volume. The relationship between density, mass and volume is defined as density equals mass divided by volume (rho = m / V). Rearranging this to solve for mass gives the formula used by this calculator: mass equals density multiplied by volume (m = rho x V). As long as you know the density of a substance and the volume you have, you can find the total mass.

The Formula

Mass = Density x Volume

For example, if you have 2 cubic metres of water, and water has a density of 1,000 kg/m3, the mass is 1,000 kg/m3 x 2 m3 = 2,000 kg (2 tonnes). This matches the calculator's default values above.

Keeping Units Consistent

The formula only works correctly if your density and volume units are compatible. This calculator handles the conversion automatically by converting whatever density unit you choose into kilograms per cubic metre, and whatever volume unit you choose into cubic metres, before multiplying them together. The common density unit conversions are:

Density Unit	Equivalent in kg/m3
1 kg/m3	1 kg/m3
1 g/cm3	1,000 kg/m3
1 g/mL	1,000 kg/m3
1 kg/L	1,000 kg/m3
1 g/L	1 kg/m3

Typical Densities of Common Materials

Water is the reference point most people know: 1,000 kg/m3 (or 1 g/cm3) at around 4 degrees Celsius, though it varies slightly with temperature. Denser materials like steel (7,850 kg/m3) and mercury (13,534 kg/m3) pack far more mass into the same volume. Lighter materials like air (about 1.2 kg/m3 at sea level) pack very little mass into a large volume. These reference values are useful for quick estimates, but for precise engineering or trade work, use the manufacturer's stated density for your specific material or product, since density varies with moisture content, temperature, alloy composition and manufacturing process.

Common Uses

Estimating the weight of a volume of concrete, sand, aggregate or timber before ordering or transporting it
Working out the mass of liquid in a tank, drum or container from its known volume
Checking whether a load will exceed a vehicle's payload or a lifting device's rated capacity
Science and engineering calculations involving fluids, materials and structural loads

Related Calculators

Science and Engineering Calculators
Density Calculator: find density from mass and volume.
Density Converter: convert between density units.
Mole to Mass Calculator: convert moles to mass using molar mass.
Volume Calculator: work out the volume of common shapes.

Sources: Standard physics definition of density (rho = m/V), as used in NCEA and university physics and engineering courses. Material density reference values are typical figures used in engineering handbooks and may vary by grade, temperature and moisture content.

This calculator provides an estimate based on the density value you enter or select. Actual material densities vary with temperature, pressure, moisture content and composition. For engineering, trade or legal purposes, confirm the exact density of your specific material or product.