I've read several pages and most of them agreed that you needed to measure 4 to 5 feet up the base of your tree, and then measure the circumference.
Tree #1 on the edge of our property next to the road
Hubby helping to measure it
What it looks like from far away, IT'S HUGE!!
124" AROUND....or in other words...
10 feet 4" circumference!!
Tree #2 further down on our property and next to the road
Practically the same exact measurement!!
So, what I was able to calculate is
Here is one method I found
Our numbers are
124/3.1416 = 39.47 if you look at the charts below that would make those trees well over 200 years old.
Here’s how to calculate a tree’s age. Warning: It helps to have a little botany background and some math skills!
1. ID the tree species (a tree field identification guide will be helpful).
2. Measure the tree’s circumference with a tape measure. Wrap the tape around the tree at chest height (about 4-5 ft up) to produce an accurate measurement.
3. Divide the circumference measurement by pi (3.1416) to yield the tree’s diameter.
4. Check the chart (below) to determine the specimen’s age.
Was your tree starting out life as DuSable was building the first cabin in Chicago in 1779? Or when Illinois was just becoming a state in 1818? Or was it sprouting from an acorn when engineers reversed the Chicago River in 1900?
This measurement technique is about 90% accurate for forest-grown trees listed on the chart.
If I use this method, and just go by the "general oak" ages on here....those trees are REALLY REALLY OLD!! They only list the white oak and red oak sooooo I'm just going by their estimations.
I found an alternate method as well
Estimating a Trees Age
The Tree Aging Formula
Begin by determining the tree species and taking a diameter measurement (or circumference measurement) using a tape measure at Diameter Breast Height or 4.5 feet above stump level. If you are using circumference, you will need to make this calculation to determine the tree diameter: Diameter = Circumference divided by 3.14 (pi)
Then calculate the age of the tree by multiplying the tree's diameter by its growth factor (see below): Diameter X Growth Factor = Approximate Tree Age. Let's use the hickory above to calculate age. A shagbark hickory's growth factor has been determined to be 7.5 and its diameter is 10 inches: 10 inch diameter X 7.5 growth factor = 75 years. Remember that the growth factors I provide are more accurate when taken for forest grown trees.
(the growth factor for our trees is about a 3.0...I THINK) so our number would be 119.1. A 119 year old tree is also really old..... :)
Now I'm of course wondering about the history of these trees since they are fairly close together and pretty close to the same size!! Did a family plant them there many years ago?? I may have to make a trip to the courthouse to research who the former property owners have been.
This was actually a pretty fun way to spend a Saturday Morning!! :)