Diameter at breast height

n. Diameter of a tree stem at a height 4.5 ft above ground level.


  • Discussion


Diameter at breast height (DBH), unless otherwise noted, is measured outside the bark (DBHOB). On sloping terrain, DBH is measured 4.5 feet above the highest ground around the tree.

DBH is can be measured by ocular estimate or using tools such as a Biltmore stick, calipers, or diameter tape (d-tape). DBH of very large trees is estimated by dividing the circumference (outside bark) by pi (3.14159).


  • Units


    Preferred units for diameter at breast height are cm in technical reports and papers. Fire Management in the United States still uses the English units in. See the following units conversion table for conversion factors for diameter at breast height.


  • Notes

    • Author 

      Joe Scott, Research Forester

      Systems for Environmental Management