Introduction
The diameter of a tree is a good indicator of its age and overall health, and guesswork is no substitute for knowing how to measure it properly. So if you want to know the size (and age) of your trees but you don’t want to hire an arborist, follow these steps for calculating the volume of your tree’s trunk correctly.
Calculate the diameter of the tree trunk for each location.
To find the diameter of your tree, you need to measure it at four locations. The best way to get an accurate measurement is with a flexible tape measure that has not been stretched. Be sure to take the measurements at each point on the trunk and then average them together for your final result.
The first place you should start measuring is at the base of your tree where it connects with its roots in soil. This location can be difficult to access if you don’t have special equipment or are unable to dig down into hard-packed soil, so try this method only if other options aren’t possible. Otherwise, look for a section where there are roots visible on both sides of the trunk – these will help give you an idea about how big around your tree is at this area too!
Next up is taking measurements around halfway up its height (or roughly where those branches start growing off). This step will give us some context as well because we know how many feet high our tree may grow before reaching full maturity – but what about length?
Use a formula to calculate the volume of the sample.
- Use the formula for the volume of a cylinder: V = πr2h
- Use the formula for the volume of a sphere: V = 4/3πr3
- Use the formula for the volume of a pyramid: V = N1L1b1h
- Use the formula for the volume of a cone: V=πh(N+H)
- Use the formula for the volume of a cube (only if you have access to this data):
Divide the volume by the space occupied by trunk cross-section.
Now that you’ve estimated the trunk height, it’s time to find the volume. To do this, multiply the area of the trunk cross-section by its depth. For example, if we have a trunk with a diameter of 50 centimeters and a depth of 30 centimeters:
- Area = pi * (diameter).(diameter) + pi * (diameter).(depth)
- Volume = area * depth
Repeat the process for all four locations of your tree.
Once you have measured the diameter of your tree trunk, use your tape measure to mark four locations around its base.
Measure the distance from the bottom of the trunk to each point on it where you will be measuring, in inches. Then measure that same distance again at 1/3, 1/2 and 2/3 of its height (these are approximate measurements).
Use your pencil and tape measure to mark each point on your tree’s circumference: The bottom; 1/3; 1/2; 2/3.
Find the average of your results.
- Find the average of your results.
You can use a calculator or an online spreadsheet to find the average, or do it by hand if you prefer. If you’re using a spreadsheet program like Microsoft Excel, for example, you can enter your numbers into separate columns and then use one of its built-in functions to calculate their mean (average).
- By hand or with computer assistance, this step is simple: add up all of your numbers and divide by how many there were total.
The diameter of a tree is a good indicator of its age and overall health, and guesswork is no substitute for knowing how to measure it properly.
The diameter of a tree is a good indicator of its age and overall health, but guesswork is no substitute for knowing how to measure it properly.
The trunk circumference is used as an indicator of tree health because it’s easy to measure at ground level, and can help estimate the overall size of a mature tree if you don’t have access to aerial photos or other resources. Branches tend to grow from the same point on each year’s growth ring on larger diameter trunks, so counting these rings will help you calculate your tree’s age by determining how many years it takes for one full circle around the trunk (or two circles if there are more than one ring per year).
Conclusion
Remember that the key to success is measuring your trees at four different locations, and then averaging their diameters. Keep in mind that this method does not take into account branch size or leaves; however, it can be an effective way to estimate a tree’s age if branches are removed before you measure it.