What this calculator does
Tree basal area works out cross-sectional trunk area at breast height (DBH), the standard forestry measure of stand density. 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 |
|---|---|
| Diameter at breast height (DBH) (cm) | A number, measured in cm. Starts at 30. |
| Stems per hectare (0 to skip) (trees/ha) | A number, measured in trees/ha. Starts at 0. |
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 diameter at breast height (dbh)
Every other input is held at the calculator’s starting values while diameter at breast height (dbh) varies. Select any row to load that scenario into the calculator.