Density to Mass Calculator
Enter density and volume to find mass instantly using the formula m = rho x V. Choose your preferred units for each quantity - metric or imperial - and the calculator converts everything internally before giving you the result in your chosen mass unit. A step-by-step panel shows the full working, a material reference table gives densities for 24 common substances, and a mass-vs-volume chart lets you see how mass scales as volume grows.
Formula
Worked example
A steel block (density 7.85 g/cm³) with a volume of 100 cm³: m = 7.85 × 100 = 785 g = 0.785 kg.
What is the density to mass formula?
Density (rho) is defined as mass per unit volume: rho = m / V. Rearranging to solve for mass gives m = rho x V. That is the only formula used here. Enter the density of a material and the volume of the sample, and the calculator multiplies them to give you mass in your chosen unit. The relationship is perfectly linear - doubling the volume at constant density doubles the mass, as the chart below this section shows.
Unit conversions used in this calculator
The calculator accepts six density units (g/cm³, g/mL, kg/m³, kg/L, lb/ft³, lb/in³) and eight volume units (cm³, m³, L, mL, ft³, in³, yd³, US gallons). All inputs are converted internally to g/cm³ and cm³ before multiplication, and the result is then converted to whichever mass unit you selected. Key conversion factors: 1 kg/m³ = 0.001 g/cm³; 1 lb/ft³ = 0.016018 g/cm³; 1 lb/in³ = 27.68 g/cm³; 1 m³ = 1,000,000 cm³; 1 ft³ = 28,316.8 cm³; 1 US gallon = 3,785.4 cm³.
How to use the material reference table
The reference table below lists densities for 24 common materials - metals, liquids, gases, and solids - so you can look up a value rather than searching elsewhere. Notice that water at 20 °C is 0.998 g/cm³, just under 1, and that density is the standard reference point: materials with density below 1 g/cm³ float on water (ice, wood, ethanol, olive oil), while those above 1 g/cm³ sink (steel, copper, lead, mercury). The densest common material in the table is osmium at 22.59 g/cm³, more than twice as dense as lead.
Practical examples of mass from density and volume
Engineering: a steel (7.85 g/cm³) shaft with a volume of 500 cm³ has a mass of 3,925 g (3.925 kg). Shipping: a carton of liquid with density 1.05 g/cm³ and volume 20 L (20,000 cm³) has a mass of 21,000 g (21 kg). Geology: a granite (2.65 g/cm³) core sample measuring 250 cm³ has a mass of 662.5 g. Chemistry lab: 5 mL of ethanol (0.789 g/cm³) has a mass of 3.945 g. In each case the arithmetic is the same - density times volume - only the numbers and units change.
Densities of common materials
| Material | Density (g/cm³) | Category |
|---|---|---|
| Air (at sea level) | 0.00121 | Gas |
| Carbon dioxide | 0.00196 | Gas |
| Ethanol | 0.789 | Liquid |
| Olive oil | 0.91 | Liquid |
| Water (20 °C) | 0.998 | Liquid |
| Seawater | 1.025 | Liquid |
| Milk | 1.03 | Liquid |
| Blood | 1.06 | Liquid |
| Mercury | 13.6 | Liquid |
| Ice | 0.917 | Solid |
| Wood (pine) | 0.5 | Solid |
| Wood (oak) | 0.72 | Solid |
| Concrete | 2.3 | Solid |
| Glass | 2.5 | Solid |
| Granite | 2.65 | Solid |
| Aluminum | 2.7 | Metal |
| Steel | 7.85 | Metal |
| Iron | 7.87 | Metal |
| Brass | 8.5 | Metal |
| Copper | 8.96 | Metal |
| Lead | 11.34 | Metal |
| Gold | 19.3 | Metal |
| Platinum | 21.45 | Metal |
| Osmium | 22.59 | Metal |
Reference densities at room temperature (~20 °C) and atmospheric pressure. Gas values are at standard conditions.
Frequently asked questions
What is the formula for mass from density and volume?
Mass equals density multiplied by volume: m = rho x V. Density (rho) is the mass per unit volume of a substance. As long as you keep the units consistent - or let this calculator convert for you - multiplying any density by any volume gives the corresponding mass.
How do I find mass if I have density in kg/m3 and volume in litres?
Convert both to a consistent unit system first. 1 kg/m³ = 0.001 g/cm³ and 1 litre = 1,000 cm³. Multiply the converted density (g/cm³) by the converted volume (cm³) to get grams, then convert to whatever unit you need. This calculator handles all those conversions automatically when you select your units from the dropdowns.
Can I use this to find volume or density instead?
This tool solves only for mass. For the other two rearrangements - volume = mass / density, or density = mass / volume - use a general density-mass-volume calculator. The formula triangle (m = rho x V, rho = m / V, V = m / rho) lets you solve for any one quantity given the other two.
Does density change with temperature?
Yes. Most materials expand when heated, increasing volume while mass stays constant, so density falls with rising temperature. Water is a notable exception near 4 °C where it reaches maximum density. The reference values in the table are for standard room temperature (roughly 20 °C) and atmospheric pressure. For precise engineering work, use temperature-corrected density values.
What is the difference between mass and weight?
Mass is a measure of how much matter an object contains (kilograms, grams, pounds-mass) and does not change with location. Weight is the gravitational force on that mass (newtons, pounds-force) and varies with gravity - on the Moon you weigh about one sixth as much, but your mass is unchanged. This calculator finds mass (not weight) from density and volume.
Why does ice float on water if ice is a solid?
Ice has a density of about 0.917 g/cm³, which is less than liquid water (0.998 g/cm³ at 20 °C). When water freezes into a hexagonal crystal lattice, the molecules are actually spaced further apart than in liquid form, so the same mass occupies more volume - making ice less dense. Any object less dense than the fluid it is placed in will float.