Wood Density Calculator
Wood density varies enormously by species — from balsa at roughly 160 kg/m3 up to dense tropical hardwoods like ipe at over 1,000 kg/m3 — so multiplying a board’s volume by its species’ density (per the USDA Forest Products Laboratory Wood Handbook) gives a reliable estimated weight at average 12% moisture content.
Quick Answer
Wood density varies enormously by species — from balsa at roughly 160 kg/m3 up to dense tropical hardwoods like ipe at over 1,000 kg/m3 — so multiplying a board’s volume by its species’ density (per the USDA Forest Products Laboratory Wood Handbook) gives a reliable estimated weight at average 12% moisture content.
Wood Density Calculator
Enter your values below for an instant result, then see the formula, worked example, and common mistakes.
Pick a species and enter dimensions, then calculate.
How to Use This Calculator
Each species has a characteristic average density at 12% moisture content (the industry-standard reference point), sourced from the USDA Forest Products Laboratory Wood Handbook and the Global Wood Density Database.
Length, width, and thickness in inches — these multiply together to give the board’s volume.
The calculator converts the species density to both kg/m3 and lb/ft3, computes the board’s volume, and multiplies by density to estimate total weight.
The listed densities assume air-dried/kiln-dried wood at about 12% moisture content. Green (freshly cut, undried) lumber holds significantly more water and can weigh 30-100% more than the same board fully dried, so treat this as a dried-wood estimate unless you know your stock is green.
Formula
Weight = Density x Volume. Volume (in cubic feet) = (Length x Width x Thickness in inches) / 1,728. Density figures used here are average values at 12% moisture content from the USDA Forest Products Laboratory Wood Handbook and the Global Wood Density Database (Chave et al. 2009; Zanne et al. 2009), which is the standard reference dataset built partly on USDA Forest Service research.
Reference Table: Average Wood Density by Species (at ~12% MC)
| Species | Density (kg/m3) | Density (lb/ft3) |
|---|---|---|
| Balsa | 160 | ~10.0 |
| Western Red Cedar | 350 | ~21.8 |
| Eastern White Pine | 420 | ~26.2 |
| Douglas Fir | 480 | ~30.0 |
| Black Walnut | 510 | ~31.8 |
| Red Oak | 560 | ~35.0 |
| White Oak | 600 | ~37.4 |
| Hard Maple | 630 | ~39.3 |
| Hickory | 670 | ~41.8 |
| Ipe | 1,040 | ~64.9 |
Values are typical averages; actual density varies within each species due to growing conditions, tree age, and the specific part of the tree the board was cut from.
Common Mistakes to Avoid
- Using “green” (freshly sawn, undried) density figures interchangeably with kiln-dried/air-dried figures — green wood can be 30-100% heavier due to retained water, so mixing up the two leads to significant overestimates or underestimates.
- Forgetting that density (and therefore weight) varies noticeably within a species due to growth rate, tree age, and growing region — published averages are a best estimate, not an exact figure for any individual board.
- Confusing specific gravity (a unitless ratio relative to water) with density in kg/m3 or lb/ft3 — specific gravity x 1,000 approximates kg/m3, but the two are not interchangeable without that conversion.
- Not accounting for defects, knots, or unusually dense/light sections of a board, which can shift real-world weight somewhat from the calculated average.
When the Estimate May Be Wrong
This calculator uses average species density values at approximately 12% moisture content. Actual board weight will differ if your lumber is significantly wetter (green/undried) or drier (kiln-dried below 12%) than that reference point, or if the specific board is denser/lighter than the species average due to natural growth variation.
FAQs
What is the density of wood used for in woodworking?
Wood density helps predict weight for shipping and handling, indicates strength and hardness (denser woods are generally harder and stronger), and affects how a wood species takes stain, glue, and fasteners.
What is the lightest common wood species?
Balsa is the lightest wood commonly used in woodworking and model-making, averaging around 160 kg/m3 (about 10 lb/ft3), though it can range from roughly 100 to 200+ kg/m3 depending on the specific tree and grade.
Does moisture content affect wood density calculations?
Yes significantly — density figures are typically standardized at 12% moisture content; green (undried) wood can weigh 30-100% more than the same wood fully dried, since freshly cut lumber retains substantial water weight.
How is wood density different from wood hardness?
Density measures mass per unit volume, while hardness (commonly the Janka hardness rating) measures resistance to denting and wear; the two are correlated (denser woods tend to be harder) but are not the same measurement.
Sources and Methodology
Species density values sourced from the USDA Forest Products Laboratory Wood Handbook: Wood as an Engineering Material (General Technical Report FPL-GTR-282, 2021) and the Global Wood Density Database (Chave et al. 2009; Zanne et al. 2009), the standard peer-reviewed reference for wood density by species, cross-checked against USDA Forest Service i-Tree Appendix 11 published density values (e.g. balsa/Ochroma pyramidale at 0.15-0.16 tonne/m3).
