Table of Contents

Weight - Volume Relationships

(1) Volume/Weight Relationship for Loblolly Sawlogs

Log Scaling Diam. Inches Weight/MBF International 1/4“ Rule
6 13,040
7 12,220
8 11,470
9 10,760
10 10,320
11 10,110
12 9,880
13 9,540
14 8,910
15 9,930
16 9,240

(Average pine = 12,666 lbs/MBF) (Koppers, Inc.)

(2) 

  Cubic foot volume of cordwood (D = average diameter)
  Solid volume of rough wood in Cu. Ft. = 4(D-6) 
  Stacked volume of rough wood in Cords = 4(D-6)/100
  Pulpwood stumpage value per tree = (4(D-6)/100) * price/cord
  Number of Trees/Standard Cord = 90/4(D-6)

Weight-Cord-Cubic Foot Relationships

Pine weight - volume conversion factors vary with species, age of stand, and distance from the coast. Thus local conversion factors should be developed for each procurement area. Illustrative of the variations existing are the average estimated weights per 128-cubic foot cord for the major pine type groups:

Type Green weight per cord Lbs.
Loblolly Shortleaf:
Texas to W. Louisiana 4700
Central Louisiana through the Southeast 5200
Longleaf-slash 5550

A cord of pulpwood from the Midsouth contains more wood now than it did 15 years ago.

Volume of wood per cord of pulpwood in the Midsouth

Region Year All Species Pine Hardwood
Cubic feet per standard cord
Midsouth 1950 – 75 78
Midsouth(1) 1965 81 81 80
East Gulf 1964 80 80 79
West Gulf 1965 82 82 81

1 East and West Gulf factors are combined in proportion to annual pulpwood production.

In a pile of wood made up of perfectly smooth cylinders of identical diameter, the solid-wood content would be the same regardless of whether the diameter was large or small. But if diameters vary, the solid-wood content increases, because small sticks fill up some of the space between large ones. On the other hand, anything that causes deviation from the cylindrical (crook or roughness, for example) will lessen the solid wood content.

When average diameter of bolts in creases, both these causes of variation operate to raise the solid-wood content. This is because the range in diameters in a pile usually becomes greater as average diameter of bolts in the pile increases, and also because large bolts tend to be less crooked and rough than small ones.