Calculator
Formula Used
Wood density: ρwood = SG × ρwater
Estimated dry density: ρdry = ρcurrent ÷ (1 + MC ÷ 100)
Estimated current density: ρcurrent = ρdry × (1 + MC ÷ 100)
Sample mass: mass = density × volume
Specific weight: γ = ρ × g
Here, SG means specific gravity. MC means moisture content. The symbol ρ means density. The value g is 9.80665 m/s².
How to Use This Calculator
Enter the wood specific gravity as a decimal value. Use 0.62, not 62%.
Enter the water reference density in kg/m³. Keep 1000 for common physics estimates.
Add moisture content if you want a dry or current density estimate.
Choose the output unit. You can display density in kg/m³, g/cm³, or lb/ft³.
Enter sample volume to estimate sample mass. Add measured mass to compare observed density.
Press calculate. The result appears above the form and below the header.
Example Data Table
| Wood sample | Specific gravity | Water density | Moisture | Base density |
|---|---|---|---|---|
| Pine sample | 0.42 | 1000 kg/m³ | 12% | 420 kg/m³ |
| Oak sample | 0.75 | 1000 kg/m³ | 10% | 750 kg/m³ |
| Teak sample | 0.65 | 1000 kg/m³ | 15% | 650 kg/m³ |
Why Wood Density Matters
Wood density shows how much mass sits inside a given volume of wood. It affects strength, hardness, shipping weight, fuel value, and machining behavior. A dense board usually carries more load. It may also resist dents better. A lighter board may be easier to cut, lift, dry, and fasten.
Specific Gravity and Density
Specific gravity compares wood density with water density. It has no unit. A value of 0.62 means the wood is 62 percent as dense as the chosen water reference. Most calculations use water near 1000 kg per cubic meter. Some reports use 62.4 lb per cubic foot. This calculator keeps the reference editable. That helps when a lab standard uses a different temperature.
Moisture Effects
Wood density changes with moisture. Water inside cell walls and pores adds mass. Shrinkage can also change volume. This tool offers simple moisture correction choices. You can convert a current density into an estimated dry density. You can also estimate current density from a dry value. These options are approximations. Use measured oven dry mass and measured volume when strict testing is required.
Practical Uses
Builders can compare species before choosing beams, flooring, trim, or furniture stock. Woodworkers can estimate board weight before transport. Students can connect specific gravity with density, mass, and volume. Inspectors can compare a measured sample with an expected species value. The optional mass and volume fields help check a real sample against the entered specific gravity.
Accuracy Tips
Enter specific gravity as a decimal, not a percent. Use the same water reference used by your source. Record whether values are dry, green, or at a stated moisture level. Measure volume carefully, because small thickness errors change density. For irregular samples, use water displacement or a lab method. Treat the result as an engineering estimate unless your inputs come from controlled testing.
Unit Choice and Reporting
The result is shown in common density units. Kilograms per cubic meter suit physics classes and engineering notes. Pounds per cubic foot suit many lumber references. Grams per cubic centimeter suit small lab samples. CSV and PDF exports make the calculation easier to archive, share, or attach to reports. Always keep units beside every stored value for clarity.
FAQs
What is wood specific gravity?
Wood specific gravity is the ratio of wood density to water density. It has no unit. It helps compare different wood species and sample conditions.
How do I enter specific gravity?
Enter it as a decimal value. For example, enter 0.58 instead of 58%. The calculator then multiplies it by the selected water reference density.
Why is water density editable?
Water density changes slightly with temperature. Some standards also use rounded values. An editable field lets you match your classroom, shop, or lab reference.
Does moisture content change density?
Yes. Moisture adds mass to wood. It may also affect volume. This calculator provides simple correction estimates, but controlled testing gives stronger results.
What is dry density?
Dry density is usually based on dry wood mass and a stated volume condition. It is useful for comparing samples without extra water mass.
Can I calculate sample mass?
Yes. Enter sample volume and choose the volume unit. The calculator multiplies final density by volume to estimate sample mass.
What is observed density check?
It uses your measured mass and volume. The tool computes observed density and observed specific gravity, then compares them with the calculated value.
Is this result suitable for design?
Use it as an estimate. For structural design, follow accepted grading rules, species data, moisture standards, and local engineering requirements.