1. Select a grade.
  2. Choose one or more species/species grouping(s). If desired, filter the species list by selecting NA for North American species only or EU for European species only. The default ALL is a combined list of both NA and EU species.
  3. Select one or more region(s)/country(ies).
  4. When satisfied with the information included on the Stamp, click “Add Stamp”.
  5. Repeat until desired number of Stamps have been added.
  6. Enter span requirements in the Design Criteria section.

For each Stamp created, the Span Options Calculator will provide the lumber sizes needed to achieve the span requirements entered.

Note: The design values shown in the table are for normal load duration and dry service conditions and are applicable to lumber surfaced either unseasoned (S-GRN) or dry (S-DRY or KD). In calculating the design values, the change in strength and stiffness that occurs as lumber dries has been taken into consideration as well as the reducing in size that occurs when unseasoned lumber shrinks. For other service conditions or load conditions, see paragraph 200 a-l in WCLB Standard No. 17 and/or the National Design Specification (NDS) Supplement published by the American Wood Council for adjustment factors.

PLIB believes the information generated by this calculator is accurate and conforms with design standards referenced by U.S. building codes.

Neither PLIB nor its members assume any responsibility for any particular design prepared from this on-line calculator. Those using this on-line calculator assume all liability and hold PLIB harmless from its use.

Please report any apparent inaccuracies to