Density to Weight Calculator
Enter a density and a volume to get the mass (weight) instantly, or flip the calc to solve for density or volume from the other two values. Switch between metric and imperial units at any time. The material density table below gives reference values for common solids, liquids, and gases so you can look up a density without leaving the page.
Formula
Worked example
A solid iron cube measuring 10 cm on each side: V = 0.10 x 0.10 x 0.10 = 0.001 m3. Iron density = 7,874 kg/m3. Mass = 7,874 x 0.001 = 7.874 kg (about 17.36 lb).
How density, mass, and volume relate
Density (rho) is the amount of mass packed into a given volume. The relationship is expressed by three equivalent formulas: mass m = rho x V, density rho = m / V, and volume V = m / rho. All three follow from the same definition - they are just rearrangements of the same equation. If you know any two of the three quantities, you can calculate the third. This calculator handles all three cases: solve for mass when you have density and volume, solve for density when you have mass and volume, or solve for volume when you have mass and density.
Using the calculator and switching units
First choose what you want to solve for using the "Solve for" selector. Then set the units for density, volume, and mass using the three unit dropdowns. Enter the two known values and the result appears instantly. The unit dropdowns support a wide range of metric and imperial units: density can be entered in kg/m3, g/cm3, lb/ft3, lb/in3, or g/L; volume in m3, cm3, litres, mL, ft3, in3, or US gallons; and mass in kg, g, lb, oz, or metric tons. All conversions happen automatically in the background, so you can mix unit systems freely. The cross-check row in the "Show your work" panel always shows the mass in every unit at once as a quick sanity-check.
Quantity field for batch calculations
The optional Quantity field multiplies the single-piece mass by the number of identical items. This is useful in manufacturing and materials planning: if you are ordering 500 steel brackets and need to know the total shipment weight, enter the bracket dimensions and density once, then set Quantity to 500. The total mass output updates immediately. For irregular shapes, break the part into primitive solids (rectangular blocks, cylinders, spheres), calculate each section separately, and add the results.
Practical applications
Density-to-weight calculations appear across engineering, science, logistics, and everyday life. In manufacturing, knowing the mass of a machined part from its CAD volume and material density is essential for structural analysis and cost estimation. In shipping and freight, knowing the actual weight of goods from volume and bulk density determines freight charges. In chemistry and materials science, density is used to identify unknown substances and to convert between volume-based and mass-based measurements. In cooking and food science, many ingredients are measured by volume but nutritional values are given by mass, so density conversions are needed. The material density table on this page covers common materials across all these domains.
Common material densities
| Material | Density (kg/m3) | Density (g/cm3) | Category |
|---|---|---|---|
| Air (dry, 20 C) | 1.20 | 0.0012 | Gas |
| Cork | 120-240 | 0.12-0.24 | Wood/Natural |
| Pine wood | 370-600 | 0.37-0.60 | Wood/Natural |
| Oak wood | 600-900 | 0.60-0.90 | Wood/Natural |
| Polyethylene (HDPE) | 940-970 | 0.94-0.97 | Plastic |
| Water (4 C) | 1,000 | 1.000 | Liquid |
| PVC | 1,300-1,450 | 1.30-1.45 | Plastic |
| Concrete | 2,000-2,500 | 2.00-2.50 | Construction |
| Glass (soda-lime) | 2,500 | 2.50 | Construction |
| Aluminum | 2,700 | 2.70 | Metal |
| Titanium | 4,500 | 4.50 | Metal |
| Steel (carbon) | 7,750-7,870 | 7.75-7.87 | Metal |
| Iron | 7,874 | 7.87 | Metal |
| Copper | 8,960 | 8.96 | Metal |
| Lead | 11,340 | 11.34 | Metal |
| Gold | 19,320 | 19.32 | Metal |
| Osmium (densest element) | 22,590 | 22.59 | Metal |
Reference densities at room temperature and standard pressure (approx. 20 degrees C, 1 atm). Use these values in the Density field.
Frequently asked questions
What is the formula for converting density to weight?
Mass = density x volume (m = rho x V). For example, if a material has a density of 2,700 kg/m3 (aluminum) and a volume of 0.005 m3, the mass is 2,700 x 0.005 = 13.5 kg. In imperial units, the same formula applies but you must keep the units consistent: lb = (lb/ft3) x ft3, or use the unit converter to mix metric and imperial freely.
What is the difference between mass and weight?
Mass is the amount of matter in an object, measured in kg or lb-mass, and it does not change with location. Weight is the gravitational force acting on that mass (W = m x g), measured in newtons. In everyday use, the two terms are used interchangeably because we live at roughly the same gravitational acceleration (9.81 m/s2). This calculator computes mass, which is what a scale displays and what is relevant for shipping, materials, and most engineering purposes.
Can I use this to find the density of an unknown material?
Yes. Select "Density (from mass and volume)" in the Solve for dropdown, then enter the mass (from a scale) and the volume (from geometry or water displacement). The calculator outputs the density, which you can compare against the reference table to identify the material. For example, if a sample weighs 89.6 g and has a volume of 10 cm3, its density is 8.96 g/cm3, which matches copper.
How do I find the volume if I know the mass and density?
Select "Volume (from mass and density)" in the Solve for dropdown, enter the mass in your preferred unit and the density in its unit, then read off the volume. This is useful when you know the material and the required mass but need to size a container or casting mold.
What density unit should I use?
It depends on the industry. Scientists and engineers typically use kg/m3 for gases and solids. Chemists often prefer g/cm3 (also written g/mL, since 1 cm3 = 1 mL exactly). Structural and civil engineers in the US commonly use lb/ft3. The calculator converts between all these automatically, so enter whatever unit appears on your datasheet and choose the output unit that suits your report.
Why is the density of a material listed as a range in the table?
Most real materials vary in density depending on grade, alloy composition, moisture content, temperature, or manufacturing process. For example, oak wood ranges from about 600 to 900 kg/m3 depending on the species and dryness. For precise calculations, use the specific density from the material datasheet or certificate rather than a generic table value.