Estimate a tree's age from diameter at breast height and typical annual diameter growth.
| Age (years) | – |
Use this calculator to estimate how old a tree may be from its trunk diameter and a typical annual diameter increment for that species. Enter the diameter at breast height (DBH) and the growth rate in centimetres per year.
The calculation is: age (years) = DBH ÷ annual diameter growth. DBH can be entered in centimetres (cm) or inches (in); the value is converted to centimetres before dividing. The growth rate is always in cm per year and is not converted. The default 1.5 cm/year is a generic hardwood figure; slow-growing oaks are often lower, and fast poplars higher.
This is a walk-in-the-woods estimate, not a ring count. It assumes roughly constant diameter growth over the tree's life, which is rarely true. A species table, a local increment core, or known planting date is more reliable.
DBH: Trunk diameter at about 1.3 m (4.5 ft) above the ground. Enter the value in cm or in.
Growth rate (cm/year): Typical increase in diameter each year, in centimetres per year. Do not convert this value when you switch the DBH unit.
Age: Estimated age in years. A result such as 40.7 years is a rounded estimate, not a precise chronology.
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