About & Methodology

We approximate the log as a smooth frustum (a tapered cylinder). The volume is computed from the small and large end diameters and the overall length. Weight is the product of volume and an estimated green density for the selected species.

Inputs can be in imperial (inches/feet, output in pounds) or metric (centimeters/meters, output in kilograms). Imperial diameters are rounded to whole numbers for ease of field entry.

- Moisture: Estimates assume green wood at roughly 75% moisture content. Actual MC varies by season, region, and storage, which affects weight.

- Geometry: The frustum model smooths out irregularities (butt flares, knots, rot pockets). Real-world logs may deviate from this ideal shape.

- Species density: We derive an estimated green density from published basic specific gravity values for each species and a category-based factor for hardwoods vs. softwoods.

Species entries include a typical basic specific gravity (dimensionless). These values are broadly available in wood technology references and academic literature. For general background reading, see:

• U.S. Department of Agriculture, Forest Products Laboratory. Wood properties and specific gravity discussions in public technical resources (general background; no specific tables reproduced here).
• Standard wood science and technology texts covering green density, moisture content, and species variability.

We do not reproduce competitor data or proprietary tables. The species list and values in this tool are compiled and normalized for estimation purposes and may differ from any single published source.

Use results as estimates, not certified weights. For transport compliance or rigging safety, verify with measured weights and follow local regulations and best practices.

If you routinely work with a specific mill or region, adjust inputs or internal factors to match your typical moisture and species mix.