About

Density miscalculation leads to material misidentification, structural overloading, and failed quality control. This tool computes volumetric mass density ρ of a cube-shaped specimen from measured side length a and mass m. The volume is derived as V = a³, then density follows from ρ = m ÷ V. Results are output in kg/m³, g/cm³, and lb/ft³. The calculator cross-references computed density against a table of 25 common engineering materials to suggest probable composition.

Accuracy depends entirely on measurement precision. A 1% error in side length propagates to approximately 3% error in volume due to the cubic relationship. Use calipers rather than rulers. This tool assumes a geometrically perfect cube with uniform density distribution. Hollow, porous, or composite specimens will yield apparent density, not true material density.

Formulas

The density of a cube is derived from its mass and the cube of its side length.

ρ = mV = ma³

Where ρ = density in kg/m³, m = mass of the cube, a = side length of the cube, and V = volume of the cube (a³).

Reverse calculations are also supported. To find side length from known density and mass:

a = √³mρ

To find mass from known density and side length:

m = ρ ⋅ a³

Error propagation: relative uncertainty in density is δρ ÷ ρ = √(δm ÷ m)² + (3 ⋅ δa ÷ a)². The factor of 3 arises because volume depends on the cube of a.

Reference Data

Material	Density (g/cm³)	Density (kg/m³)	Density (lb/ft³)	Category
Balsa Wood	0.16	160	9.99	Wood
Cork	0.24	240	14.98	Natural
Pine Wood	0.51	510	31.84	Wood
Oak Wood	0.72	720	44.95	Wood
HDPE Plastic	0.95	950	59.31	Polymer
Water (ref.)	1.00	1000	62.43	Liquid
PVC Plastic	1.40	1400	87.40	Polymer
Concrete	2.30	2300	143.58	Composite
Glass	2.50	2500	156.07	Ceramic
Granite	2.70	2700	168.56	Stone
Aluminum (Al)	2.70	2700	168.56	Metal
Marble	2.71	2710	169.18	Stone
Titanium (Ti)	4.51	4510	281.56	Metal
Chromium (Cr)	7.19	7190	448.87	Metal
Tin (Sn)	7.30	7300	455.74	Metal
Cast Iron	7.30	7300	455.74	Metal
Steel (Carbon)	7.85	7850	489.87	Metal
Stainless Steel	8.00	8000	499.42	Metal
Brass	8.50	8500	530.63	Alloy
Nickel (Ni)	8.91	8910	556.22	Metal
Copper (Cu)	8.96	8960	559.34	Metal
Silver (Ag)	10.49	10490	654.85	Metal
Lead (Pb)	11.34	11340	707.93	Metal
Tungsten (W)	19.25	19250	1201.78	Metal
Gold (Au)	19.32	19320	1206.15	Metal
Platinum (Pt)	21.45	21450	1339.14	Metal
Iridium (Ir)	22.56	22560	1408.41	Metal
Osmium (Os)	22.59	22590	1410.28	Metal

Frequently Asked Questions

Since volume scales as a³, a relative error of δa in side length produces approximately 3 × δa relative error in volume. A 2% side length error yields roughly 6% volume error and thus 6% density error. Always use precision calipers with at least 0.01 mm resolution for small cubes.

The tool cross-references your computed density against a table of 28 common materials and returns the closest matches within ±5% tolerance. However, many materials share similar density ranges. For example, Aluminum and Granite both sit near 2.70 g/cm³. Positive identification requires additional tests such as hardness, conductivity, or spectroscopy.

The volume formula V = a³ is valid only for a regular hexahedron with six identical square faces. If your specimen has rounded edges, surface pitting, or dimensional variation between faces, measure all three axes independently and use the rectangular prism formula V = l × w × h instead. Deviations exceeding 1% from cube geometry will introduce systematic error.

True density refers to the density of the solid material itself, excluding any internal voids. Apparent (or bulk) density includes enclosed porosity and air pockets. A porous ceramic cube may show apparent density of 1.80 g/cm³ while its true material density is 2.50 g/cm³. This calculator computes apparent density from external dimensions.

Yes. Most materials expand when heated. Steel has a linear thermal expansion coefficient of approximately 12 × 10⁻⁶ K⁻¹. A 100 K temperature increase changes its linear dimension by 0.12% and volume by 0.36%. For most engineering purposes below 200 °C, this effect is negligible. Standard reference temperature is 20 °C (293.15 K).

For cubes with mass under 10 g, use an analytical balance with 0.001 g resolution. Tare the balance before placing the specimen. Avoid drafts and static electricity. For hygroscopic materials, weigh immediately after removing from a desiccator. Record mass to at least 4 significant figures to maintain density precision within 1%.