What this calculator does
Tree diameter at breast height (DBH) works out trunk diameter and cross-sectional area from a measured circumference. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
The inputs explained
| Field | What to enter |
|---|---|
| Circumference at breast height (in) | A number, measured in in. Starts at 94.2. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with circumference at breast height
Every other input is held at the calculator’s starting values while circumference at breast height varies. Select any row to load that scenario into the calculator.