Why Do We Have Hardwood Lumber Grades and What Do They Mean?

For someone just beginning to purchase hardwood lumber, lumber grades can be overwhelming. Most lumber companies use the generally accepted grading rules set by the National Hardwood Lumber Association.

To help you understand what these grades mean, here’s a short description on those grades.

What Does a Lumber Grade Mean?

Grades are based on the amount of usable clear material in a board. The highest grade boards are FAS and Select, followed by #1 Common and #2 Common. What grade you choose depends on your project. Some projects, such as tabletops and high quality furniture, may dictate the highest grade available. Many other projects are just as easily adapted to #1 Common (often referred to as cabinet grade) – kitchen cabinet doors, smaller projects and items where some character is acceptable.


A lumber grader inspects lumber to designate a lumber grade.

About Hardwood Lumber Grading

The National Hardwood Lumber Association (NHLA: www.natlhardwood.org) rules were designed to provide the furniture industry a mathematically measurable method to grade lumber for its amount of clear, defect free wood. Since then, they’ve been be adopted across the hardwood industry as a way to consistently provide a similar product to customers time and time again.

Hardwood grades are based on the size and number of clear pieces that can be obtained from a board when it is cut up to be used to make a product. Grades are not determined by gut reactions to what a person thinks the grade should be, but actual measurements of clear sections and definitions for defects.

In practice, some of the above grades are rarely used in the commercial trade and others are typically combined. For example, lumber graded “Select & Better” would include FAS, F1F, and Select boards.

What Lumber Grade Should I Use?

The upper grades, FAS, F1F and SEL, are most suitable for mouldings, joinery products such as door frames, architectural interiors and furniture requiring a high percentage of long wide cuttings. It should be noticed that FAS – the highest grade – is not synonymous with being 100% clear material.

The Common grades are likely to be most suitable for the cabinet industry, most furniture parts and flooring. Explore the use of the common grades to achieve the most value considering lumber cost and yield.

The Steps in Determining Lumber Grade:

  1. Determine species.
  2. Calculate the Surface Measure (SM).
  3. Determine the poor side of the board.
  4. From this poor face, calculate the percentage of clear wood available.

Note: If Number 1 Common is the grade of the poor face, check the better face to see if it will grade FAS for the F1F or Selects grades to be achieved.

  1. Once the grade is determined, check for any special features such as sapwood or heartwood cuttings for special color sorts.
  2. Sort to bundles according to buyer and seller specifications.



For a full illustrated guide to the various grades.

Learn more about NHLA.