Doyle Scale vs. International Scale
When a timber buyer measures your trees and tells you how many board feet they contain, they are using a log scale. A log scale is a system for estimating how much lumber a log will produce. Two of the most common log scales in Ohio are the Doyle Scale and the International Scale. The scale that is used matters because it directly affects the numbers on the table and the amount of money you receive.
What a log scale does
A log scale is a way to estimate the board footage of a log based on its diameter and length. It does not measure the wood inside the tree directly. Instead, it uses a formula or a printed table that gives an estimated lumber volume. Mills use these scales to figure out how much lumber they can expect to recover, and buyers use them to calculate what they are willing to pay.
Different log scales give different numbers. That is why it is important to know which one is being used before you agree to anything.
The Doyle Scale
The Doyle Scale is one of the oldest and most widely used log rules in the eastern United States. It is familiar to many buyers and mills, which is why it is still common today.
Doyle is conservative on smaller logs. It often reports fewer board feet than what will actually come out of the log once it is sawn. On larger logs, the Doyle numbers are closer to reality. If someone uses Doyle on a 14-inch log, the result can be much lower than what you would see with another scale.
Because Doyle often gives lower numbers, it can make a timber sale appear to have less volume than it actually does.
The International Scale
The International Scale was developed to provide more accurate and consistent estimates of lumber volume across all log sizes. It accounts for saw kerf and taper, which makes it a more realistic estimate of what a sawmill will actually produce.
Many foresters prefer the International Scale because it tends to give a fairer and more consistent measure of the volume in both small and large logs. If a buyer and a forester scale the same logs, the International numbers are usually higher than Doyle, especially for small and medium logs.
Doyle vs. International at a glance
| Feature | Doyle Scale | International Scale |
|---|---|---|
|
Used by |
Traditional mills and buyers in the eastern US |
Professional appraisers and foresters |
|
Accuracy |
Low on small logs, moderate on larger logs |
Consistent across all sizes |
|
Volume estimates |
Conservative |
Closer to actual mill recovery |
|
Effect on price |
Can make sales look smaller |
Reflects a truer value |
Why this matters to landowners
If a buyer uses Doyle, the estimated volume will often be lower. That lower number affects what they offer to pay. If your timber is appraised with the International Scale, the estimate may be higher and closer to the true value of your timber. This can mean more money for you.
When a sale is based on Doyle, you are working with smaller numbers from the start. That can make it harder to compare bids fairly if different buyers or foresters use different scales.
A practical example
Imagine a 16-foot log with a 14-inch diameter.
On Doyle, the log might scale at 80 board feet.
On International, the same log might scale at 110 board feet.
That difference adds up quickly when a tract contains hundreds of trees. This is especially true with white oak and black walnut trees, where the difference can be tens of thousands of dollars. You simply cannot trust timber buyers.
A simple way to protect yourself
Before you agree to sell, ask what log scale the buyer will use. If you have the timber appraised with the International Scale, you will have a clearer picture of the true volume on your land. You can then compare bids on equal footing and avoid surprises at settlement.
Final thoughs
Knowing which log scale is being used is a key part of protecting your timber investment. The Doyle Scale is still common, but it can understate the volume in smaller logs. The International Scale is more accurate across the board. A good consulting forester can help you understand the numbers and make sure your timber is valued fairly.
If you are preparing to sell timber, your forester will get an appraisal that uses the International Scale so you know the real numbers before buyers start bidding.
- Minimum: 10 wooded acres or 50 mature trees.