How to Measure Trees

Following these steps should allow you to get a close estimation of your trees’ circumference, height, and spread just for fun or to nominate a tree for either the Legacy Tree or Champion Tree programs. Tree measurement is easiest to do with two people.

Massachusetts Legacy Tree Program

The Details of How to Measure Trees

What you need for How to Measure Trees

  • Measuring tape
  • Ruler
  • Clinometer (optional)
  • Calculator

How to view How to Measure Trees

Please be sure you have obtained permission from the property owner before accessing a property to measure a tree.

Next steps for How to Measure Trees

  1. Measure Circumference

    Tree circumference is measured at 4.5 ft. height on the trunk. It is easiest to measure with a flexible tape measure, but a string can be used to mark the circumference and then measured with a ruler or rigid measuring tape. Wrap the tape measure around the girth of the tree, trying to keep the tape 90 degrees to the natural lean of the tree.

    Measuring the Circumference of a Tree
    Measuring the Circumference of a Tree
  2. Measure Height

    Method 1 –Using a clinometer

    If you have a clinometer, and don’t mind doing a little math, this method is more accurate for determining tree height. Stand a distance back from the tree at a point where you have a good view of the crown. Use the clinometer to determine the angle from your position to the highest point on the tree. Then, using a measuring tape, measure the distance from your location to the trunk of the tree. Use the following equation to calculate the height, you will need a calculator to find the tangent of the angle reading from the clinometer and multiply this value by the distance to the tree trunk. Finally, add your height to result to find the final tree height.

    Height= tangent (clinometer angle) x distance to tree trunk

    Final tree height= height + recorders height

    Measure a Tree Height Using a Clinometer
    Measure a Tree Height Using a Clinometer

    Method 2- Using a ruler

                Stand a distance away from the tree where you can see the entire tree in your field of view. Hold the ruler upright in your hand with your arm extended out fully. Line the ruler up with the tree so the top of the ruler aligns with the highest point of the tree; mark on the ruler with your thumb the tree base. Keeping your arm extended, turn the ruler 90 degrees. Either have your measuring assistant stand at the point on the ground out from the tree where you see the ruler end or note the point where the ruler ends. Measure the distance from either the person or the spot to the tree base, this distance is equivalent to the trees total height.

    Measure Tree Height Using a Ruler
    Measure Tree Height Using a Ruler
  3. Measure average spread

    To measure the spread of a trees’ crown, have two people stand at opposite extents of the crown directly under the furthest extent of growth. Measure the distance between the two using a measuring tape. A minimum of two measurements are need to determine the average spread, typically you will use the distance of the widest part of the crown and the distance of the shortest part of the crown.

    Measure the Ave. Spread of a Tree
    Measure the Ave. Spread of a Tree

More info about How to Measure Trees

For more detailed tree measuring guidelines, check out the American Forests Measuring Guidelines Handbook  

Contact for How to Measure Trees

DCR Bureau of Forest Fire Control and Forestry, Urban and Community Forestry Program
251 Causeway Street, Suite 900, Boston, MA 02114