The Tree Basal Area from Circumference calculator computes the basal area for a tree based on the tree's diameter at breast height.

INSTRUCTIONS: Choose units and enter the following:

• (CBH) Tree Circumference are Breast Height (~4'6" from the ground)

Tree Basal Area from Diameter (BA): The basal area is returned in square feet (ft²). The approximate diameter at breast height is also returned in inches.  However, these can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The basal area of a tree is a measure of the cross-sectional area of a tree trunk at breast height (typically 1.3 meters or 4.5 feet above the ground). It is commonly used in forestry to estimate the density of trees in a given area, assess forest stand structure, and calculate timber volume.

The basal area is calculated using the formula for the area of a circle:

A = π ⋅ d²/4

where:

• A = Basal Area of a tree at breast height
• d = Diameter of a tree at breast height (DBH).

Unit Conversion

Basal area is often expressed in square feet per acre (ft²/ac) and square meters per hectare (m²/ha) when assessing forest stands.

Importance in Forestry:

Basal area is used to estimate the volume of timber that can be harvested.  Basal area helps in assessing the health and productivity of a forest stand. It is used in forest management practices to determine thinning and other treatments. By summing the basal areas of individual trees in a sample plot, foresters can estimate the total basal area per hectare, which is an important indicator of forest density and stand structure.

Forestry Calculators

• Tree Basal Area from Diameter: Computes the basal area of a tree based on the measurement of the tree's diameter at breast height.
• Tree Basal Area from Circumference: Computes the basal area of a tree based on the measurement of the tree's circumference at breast height.
• Basal Area per Acre: Computes the basal average per acre (ft²/ac) and basal average per hectare (m²/ha), based on samples and plot size.
• Volume of Maple Syrup from Sap: Computes the amount of maple syrup produced from an amount of sugar maple sap.
• Value of Maple Syrup Harvest: Computes the dollar amount associated with a number of sugar maple tree taps.
• Acreage Sample Ring: Compute the radius of a circle (e.g., 37 ft) where the area of the circle equates to an input area (e.g., 1/10^th acre)
• Square Meters to Acres: Converts square meters to acres.
• Simple Stats: Computes the most common observational statistics (min, max, mean, sd, sum, sort etc) for a set of comma separated numbers.