Density of Wood: Species Chart, Hardwood vs Softwood, and Float Test

All density values are for air-dried wood at approximately 12% moisture content (standard reference condition). Green (freshly cut) wood can be 50–100% heavier due to water content. Kiln-dried wood is slightly lighter than air-dried.

The values below are reference densities for air-dried wood at approximately 12% moisture content. Within the same species, real density can vary by about ±10% depending on origin, growth conditions, and individual tree variation.

Woods with density above 1,000 kg/m³ (ebony, lignum vitae, some ironwoods) will sink in fresh water. Most commercially used woods float. See the float test section below for the full explanation.

For comparisons against metals, plastics, liquids, and building materials, open the density table.

The terms "hardwood" and "softwood" are botanical classifications, not hardness ratings. Hardwoods come from deciduous angiosperm trees (broad-leaved, flowering plants). Softwoods come from coniferous gymnosperm trees (needle-bearing, cone producers). Balsa — one of the lightest and softest woods commercially available — is botanically a hardwood because it comes from a flowering tree.

Despite the naming, density ranges overlap significantly. Many softwoods (southern yellow pine at 590 kg/m³, yew at 670 kg/m³) are denser than many hardwoods (poplar at 420 kg/m³, alder at 450 kg/m³). Density is a better predictor of strength and hardness than the hardwood/softwood label.

Janka hardness — the standard measure of wood's resistance to denting and wear — correlates strongly with density. Denser woods are generally harder. This is why high-density species like hickory (820 kg/m³) and hard maple (705 kg/m³) are preferred for flooring and tool handles, while lower-density species like pine and cedar are easier to work but dent more easily.

Whether wood floats depends entirely on whether its density is above or below that of the liquid it is placed in. Fresh water has a density of about 1,000 kg/m³; see the density of water reference for the temperature details. Any wood with a density below 1,000 kg/m³ will float in fresh water; any wood above 1,000 kg/m³ will sink. For the underlying principle, see what is density.

The vast majority of commercially used woods have densities well below 1,000 kg/m³ and float readily. Even dense hardwoods like white oak (770 kg/m³) and hickory (820 kg/m³) float in fresh water, though they sit lower in the water than lighter species.

A small number of exceptionally dense woods sink in fresh water:

Note: In salt water (~1,025 kg/m³), the threshold shifts slightly higher — some borderline ironwoods that sink in fresh water may float in sea water.

Moisture content (most significant variable): Wood density values are always quoted at a specific moisture content because wood absorbs and releases water significantly. At 12% moisture content (air-dried, the standard reference), a species might measure 600 kg/m³. The same wood freshly cut (green) at 80–100% moisture content could weigh 900–1,000 kg/m³. Kiln-dried wood at 6–8% moisture content would be slightly lighter than the air-dried value.

Cell structure and porosity: Wood is a cellular material. Denser woods have thicker cell walls and smaller cell lumens (the hollow interior of each cell), leaving less air space per unit volume. Less dense woods have thinner walls and larger air spaces. This cellular structure also explains why wood is an effective thermal insulator — the trapped air reduces heat transfer.

Growth rate and ring density: Slow-growing trees generally produce denser, tighter-grained wood than fast-growing trees of the same species. Old-growth timber is typically denser than plantation timber. In ring-porous hardwoods, the proportion of dense latewood (summer growth) to less dense earlywood (spring growth) directly affects the board's average density.