A board foot is a unit of measurement for lumber volume. It represents a volume of 1 foot long × 1 foot wide × 1 inch thick. When applied to logs, the board foot calculation estimates the usable lumber that can be extracted from raw timber. The Log Board Foot Calculator is designed to make this computation simple by using standardized formulas. It’s especially useful for foresters, mill operators, and lumber buyers who need reliable volume estimates for pricing and planning purposes.
Detailed Explanations of the Calculator’s Working
The Log Board Foot Calculator uses inputs such as the diameter (in inches) at the small end of the log and the total log length (in feet). It applies a mathematical formula to estimate the volume of lumber in board feet. Many calculators use either the Doyle Rule, Scribner Rule, or International 1/4" Rule, but a simplified version is commonly used for quick estimates. This version calculates volume based on diameter squared, multiplied by length, then divided by a constant to standardize the unit. The result is an accurate and fast approximation of board footage, enabling better planning and financial forecasting.
Formula with Variables Description
Where:
Diameteris the small-end diameter of the log in inchesLengthis the total log length in feet144is the conversion constant to adjust the result into board feet
This formula assumes a cylindrical approximation and is typically used for logs with relatively uniform dimensions.
Quick Reference Table: Estimated Board Feet by Log Size
| Diameter (inches) | Length (feet) | Estimated Board Feet |
|---|---|---|
| 10 | 8 | 5.56 |
| 12 | 10 | 10.00 |
| 14 | 12 | 16.33 |
| 16 | 16 | 28.44 |
| 18 | 20 | 45.00 |
| 20 | 20 | 55.56 |
| 24 | 16 | 64.00 |
| 28 | 12 | 65.33 |
Use this table for quick estimates without needing a calculator on-site.
Example
Let’s calculate the board feet of a log with a diameter of 16 inches and a length of 12 feet.
Using the formula:
Board Feet = (16² * 12) / 144
= (256 * 12) / 144
= 3072 / 144
= 21.33 board feet
This means the log yields approximately 21.33 board feet of usable lumber. The calculator performs this instantly, eliminating the risk of manual error.
Applications with Subheadings
Forestry and Timber Harvesting
Logging professionals rely on board foot estimates to determine timber yield and to price logs accurately. The calculator helps identify high-value trees and improves resource management.
Lumberyard Operations
Sawmills use board foot calculations to assess incoming logs and plan cutting strategies. Accurate estimates ensure better inventory control and customer satisfaction.
DIY and Construction Projects
Builders and woodworkers planning custom furniture, sheds, or framing work use the calculator to avoid overbuying or running short on material. It supports cost-effective project planning.
Most Common FAQs
Board foot measurement provides a standard unit for pricing lumber. Instead of pricing by weight or raw log size, the board foot reflects the usable volume of wood. This ensures consistent valuation across different log sizes and species, making it easier to compare prices and make purchasing decisions.
These are log rules that offer different estimations of board feet. The Doyle Rule underestimates small logs but is easy to calculate. The Scribner Rule is based on 1-inch boards with kerf allowances, often used in the western U.S. The International 1/4" Rule is more precise and accounts for taper and kerf, making it more reliable for commercial estimates. The calculator typically uses a simplified average unless otherwise specified.
The calculator provides estimates for relatively cylindrical and straight logs. For highly irregular or curved logs, professional volume assessment tools or 3D modeling techniques may yield more accurate results. Nonetheless, the calculator still offers a useful baseline estimate.
Yes. The formula applies regardless of the wood species. However, density and shrinkage may vary between hardwoods and softwoods, affecting actual usable board feet after processing. For pricing or load-bearing considerations, you may need species-specific adjustments in professional settings.