Tree Age Calculator

[kac]

https://www.tree-guide.com/tree-age-calculator

For those that ask why? If you look carefully you will see groups of trees of similar sizes in patches. This can mean many things such as forgotten farm land or even areas that once had structures. Also helps to get an idea when scouting areas that you may have seen on an old map of a given period.

[GB_Amateur]

I like the concept and understand the reason you posted it as I often want to use this info to age a site, etc.  However, their selection of trees is limited and after doing two test queries, I'm skeptical of their answers.  If it weren't raining outside I'd go measure a couple old trees for which I know the age, to get a better test.  When it stops raining I'll do that.

[UT Dave]

Trees can be a good tell, for sure.

Saturday I was hunting a fairly new soccer park, too new for silver coins.  I remember when it was built, about 40 years ago.  We used it as a motocross track before that.

Nothing very deep on the soccer fields, under the sod/soil only about 5" deep was a base layer of gravel.  But along the east edge of the park, are some old trees.  It's a part of the park that looks particularly unappealing and doesn't see much traffic, so not necessarily an obvious place to hunt.  But, I know those trees were there long before the park was built, they were big mature trees 40 years ago. So, not getting anything but clad and tiring of Corona caps and aluminum trash digging low numbers hoping for jewelry on the soccer field, I wandered over there to the old trees.

Different colored dirt.  Re adjusted GB.  And no gravel layer underneath, getting much deeper targets.  Pulled a couple of old shotshell butts from 8".  Few other non-ferrous junk.  Then a '64 Rosie from 8" deep!  In a "new" park.  Had to be a drop from before the park was built.  Old trees led me to it.  Not the first time old trees have put me on something good.

- Dave

[kac]

Gives a good ball park +- 10 years. I may make a quick reference chart I can print out and laminate.

[Joe Beechnut OBN]

Very cool calculator, I've been curious about the age of a few of the Oaks in my backyard..236 and 226 years old.. Not exact but gives me a ball park idea.

[kac]

Found growth factors chart so simply multiply the growth factor with the dia of the tree. I sorted them as many trees have similar growth rates. Site says 4ft up for measurement. They also noted that trees in the open area have lower growth rates.

Original source is here:

https://goodcalculators.com/tree-age-calculator/#Tree Species & Growth Factors

Black Willow	2
Quaking Aspen	2
Basswood	3
Box Elder	3
Honeylocust	3
Kentucky Coffee Tree	3
Littleleaf Linden	3
Pin Oak	3
Shumard Oak	3
Silver Maple	3
Tulip Tree	3
River Birch	3.5
Scotch Pine	3.5
American Elm	4
American Sycamore	4
European Beech	4
Green Ash	4
Northern Red Oak	4
Scarlet Oak	4
Sweetgum	4
Austrian Pine	4.5
Black Walnut	4.5
Colorado Blue Spruce	4.5
Norway Maple	4.5
Red Maple	4.5
Black Cherry	5
Black Maple	5
Douglas Fir	5
European White Birch	5
Norway Spruce	5
White Ash	5
White Birch	5
White Oak	5
White Pine	5
Yellow Buckeye	5
Red Pine (Norway Pine)	5.5
Sugar Maple	5.5
erican Beech	6
Shingle Oak	6
Cottonwood2Dogwood	7
Ironwood	7
Redbud	7
Shagbark Hickory	7.5
White Fir	7.5
Common Horsechestnut	8

[GB_Amateur]

2 hours ago, kac said:

Original source is here:

https://goodcalculators.com/tree-age-calculator/#Tree Species & Growth Factors

That's a different calculator than the one in your initial post, right?  (The first is based on data taken in Europe, I think.  At least it references a link with a prefix ".de" -- Deutschland, i.e. Germany.)

The current link (quoted here in this post, from kac) looks to be North American species.  But even for that, I measured a pin oak in my back yard for which I have two sources of info on its age, the most reliable being Historic Aerials (other from an arborist's estimate which is consistent).  It was not there in 1965, so less than 57 years of age.  Website calculator says ~92 years.  My neighbor has a silver maple which also wasn't there in 1965.  I could measure it, too, but I'd rather ask permission first.  They'll wonder "what is that crazy metal detectorist neighbor doing now?!" if I just go over and start hugging their tree.  😁

Update:  measured another tree (tulip poplar in my yard) which is also not in the 1965 aerial photo.  Calculator says 79 years of age.  I think both these trees were planted when or right after the house was built (1969 ==> 53 years ago.)  So in my cases the calculator is high by 75% and 50% respectively.  Maybe not quite that far off assuming they were saplings when put here as opposed to seeds.

Rainfall (and amount of sunlight?) has to be a big factor and giving one number for a large geographic area (even if the climate determines where different species grow) likely leads to large uncertainties.

[kac]

5 hours ago, GB_Amateur said:

That's a different calculator than the one in your initial post, right?  (The first is based on data taken in Europe, I think.  At least it references a link with a prefix ".de" -- Deutschland, i.e. Germany.)

The current link (quoted here in this post, from kac) looks to be North American species.  But even for that, I measured a pin oak in my back yard for which I have two sources of info on its age, the most reliable being Historic Aerials (other from an arborist's estimate which is consistent).  It was not there in 1965, so less than 57 years of age.  Website calculator says ~92 years.  My neighbor has a silver maple which also wasn't there in 1965.  I could measure it, too, but I'd rather ask permission first.  They'll wonder "what is that crazy metal detectorist neighbor doing now?!" if I just go over and start hugging their tree.  😁

Update:  measured another tree (tulip poplar in my yard) which is also not in the 1965 aerial photo.  Calculator says 79 years of age.  I think both these trees were planted when or right after the house was built (1969 ==> 53 years ago.)  So in my cases the calculator is high by 75% and 50% respectively.  Maybe not quite that far off assuming they were saplings when put here as opposed to seeds.

Rainfall (and amount of sunlight?) has to be a big factor and giving one number for a large geographic area (even if the climate determines where different species grow) likely leads to large uncertainties.

Ya different calculator. There are many factors that effect tree growth so I'm sure there are some big variations. Best way is to take a core sample or cut the tree down and count rings but this is non destructive and I'm pretty sure your neighbor would rather have a tree hugger next door 🙂

If you have a tree and know the age simply take the years/dia = factor.

I'll check around here and see how the numbers compare.

[GB_Amateur]

1 hour ago, kac said:

Best way is to take a core sample or cut the tree down and count rings...

Actually coring (taking a small diameter cylinder of material cut transverse to the age rings) is non-destructive.  I don't know what it costs to analyze that, though.  Likely too much for the typical detectorist.  Studying the tree to determine age is one clue which can be combined with others -- research for sure but also reading of the terrain, etc.  Of course you know all this stuff as it's helped you in your detecting sites.

[kac]

13 hours ago, GB_Amateur said:

Actually coring (taking a small diameter cylinder of material cut transverse to the age rings) is non-destructive.  I don't know what it costs to analyze that, though.  Likely too much for the typical detectorist.  Studying the tree to determine age is one clue which can be combined with others -- research for sure but also reading of the terrain, etc.  Of course you know all this stuff as it's helped you in your detecting sites.

Think you need to find someone that works for less than min wage to count the rings...