Log Board Foot Calculator: Estimate Lumber Yield From a Log

If you are planning to mill logs, the first thing that comes to mind is, “What will be the amount of lumber that I will be able to produce from this particular log?” This is where our Log Board Foot Calculator becomes handy, as it lets you estimate the possible amount of lumber that you can produce from the log before you ship it to the sawmill.

While a board foot calculator deals with boards, a log calculator takes into consideration the diameter and length of the log to calculate its yielding volume of lumber.

What Is a Log Board Foot?

A board foot represents a volume of lumber equal to 1 inch thick, 12 inches wide, and 1 foot long.

A log does not have uniform rectangular dimensions, so you cannot simply multiply its diameter by its length to get an exact board-foot yield. Instead, log scaling formulas estimate how much lumber the log may produce after sawing.

The actual yield can vary because of the log’s shape, taper, defects, saw kerf, and the way the sawmill cuts the log.

What Does a Log Board Foot Calculator Calculate?

Common measurements used by the log board foot calculator include:

• Log diameter
• Log length
• Log scaling method or log rule where applicable

 

There are some log board foot calculators that require you to choose a particular scaling method, for example, the Doyle scaling, Scribner scaling, and the International 1/4-inch scaling.

So, using the chosen scaling method, the calculator gives an estimate of how many board feet there are in the log.

It is important to note that two scaling methods can give different estimates for the same log.

Log Board Foot Formula:

The log board foot formula used varies according to the formula of the log scaling.

For instance, the Doyle formula makes use of the logarithm of the diameter and the length of the log in estimating the volume of board-foot.

Yes. In case you are using the Doyle log rule, the simplified Doyle formula is:

Where:

• D = Small-end diameter of the log in inches

• L = Length of the log in feet

• 4 = The allowance of the Doyle rule for slab and waste

 

Example Calculation:

If you are using the Doyle log rule, the formula is:

Example:

Suppose you have a log with a diameter of 18 inches and 8 feet in length.

Put the figures into the equation:

Calculation Step by step:

18 – 4 (Doyle allowance for waste) = 14

14² = 196

196 x 8 = 1,568

The Doyle rule divides the calculation above by 16 in accordance with its formula.

Thus,

1,568 ÷ 16 = 98

Answer:

A log of 18 inches and 8 feet gives 98 board feet in the Doyle rule.

 

Note: 98 board feet is only an estimate in the Doyle rule of log scaling. It does not necessarily mean that you will be able to cut out 98 board feet from the log. However, actual recovery may vary due to taper, knots, defects, saw kerfs, and milling techniques. In addition, log rules give an approximation, and there may be variations in results using various scaling systems.

Example Log Board Foot Estimates:

Log Diameter	Log Length	Estimated Board Feet
12 inches	8 feet	32
14 inches	8 feet	50
16 inches	8 feet	72
18 inches	8 feet	98
20 inches	8 feet	128

 

So, we can now clearly see how diameter affects the board feet volume.

How to Use a Log Board Foot Calculator?

Entering the data into the calculator involves only a few simple steps.

1. Measuring Log Diameter

Measuring the diameter is required at the right end of the log in accordance with the scaling technique used by your calculator. Some scaling techniques require measuring the diameter of the small end of the log inside the bark.

2. Measuring Log Length

Measure your log in feet. If there are many logs, measure each one separately.

3. Selecting a Scaling Rule

When you have different choices of scaling rules, choose the one that is necessary for your sawmill, timber purchaser, or other purposes.

4. Entering the Data into the Calculator

Enter the diameter and length of the log into the corresponding sections.

5. Calculating the Yield

The calculator calculates the estimated yield of board feet of lumber from the provided data.

 

Note: If you’re comparing several logs, calculate each one separately and add the results.

Why Does Log Shape Matter?

Although two logs may be of the same size, the quantity of lumber obtained from them will vary from one log to the other.

so , logs that are straight, healthy, and free from defects are more suitable for milling than those with taper, knots, splits, decay, or sweep.

Moreover, it is impossible for the calculator to consider all of the attributes of each specific log. Treat the output of the calculator as just an estimate, rather than a promise of yield. This is particularly true if you are evaluating the worth of valuable hardwood logs.

Log Board Feet vs. Board Feet

A Board Foot Calculator determines the volume of wood once you determine its thickness, width, and length.

The Log Board Foot Calculator, however, predicts the potential lumber volume that a round raw log can yield.

For instance, after cutting a log into boards, you can use the board-foot calculator to find the volume of the boards. On the other hand, even before the log is cut, the log calculator provides you with an estimate of its potential volume.

Log Board Feet vs. Linear Feet

It is important that you do not confuse board feet with linear feet.

The Linear foot calculator measures length only, whereas the log board feet calculation provides the volume of lumber and takes the diameter and length of the log into consideration.

What Factors Influence Lumber Yield?

The possible lumber yield that we calculate from the calculator may not match the actual quantity of usable lumber due to:

• Log taper
• Knots or other defects
• Crack or rot damage
• Saw kerfs
• Slab or edge cuts
• Milling process
• Thickness of board
• Grade considerations

 

For example, the sawmill may remove pieces with considerable defects rather than mill the whole log into fine and usable pieces of wood. Therefore, it will lessen the amount of saleable wood than estimated.

Frequently Asked Questions (FAQs)

How do I determine the board feet in a log?

You need to determine the right diameter of the log and its length and use the right scaling rule for the board feet calculator that you are using. Formulas of different scaling rules may give you different answers.

How many board feet are there in a 16-inch diameter 8 foot long log?

If you want to know the number of board feet in a 16-inch diameter 8-foot long log, using the Doyle formula, you will get 72 board feet.

How accurate is the calculation using a log board foot calculator?

The calculation using the log board foot calculator will give you an estimate of the board feet but not the exact value. There are many factors influencing this estimation.

Use Our Log Board Feet Calculator Instantly:

Wrapping up, with the use of our Log Board Foot Calculator, you will have a good basis for how much lumber can be generated out of a log. Make sure that the measurement you will input is correct, choose the right scaling system, and remember that the actual yield will vary based on the condition of the log itself.

You can get the most accurate results by comparing the calculator’s results with your local sawmill’s scaling system.