Tree Value Calculator
Enter your tree's diameter, height, species, and condition to get two complementary estimates: the ornamental appraisal value used by arborists (CTLA Trunk Formula Method), and the timber stumpage value based on board-foot volume. Switch between metric and imperial units, and the results update instantly. Use the step-by-step panel to follow the full calculation.
Two ways to value a tree
A tree can be valuable in two very different senses. As a living asset in the landscape, it provides shade, beauty, wildlife habitat, and property appeal - this is the ornamental or amenity value, measured by the CTLA Trunk Formula Method developed by the International Society of Arboriculture (ISA). As a harvestable raw material, its standing timber has a stumpage value based on the volume of usable lumber it contains. These two numbers often differ by an order of magnitude, and knowing both helps you make informed decisions about whether to preserve, harvest, or replace a tree.
How the CTLA Trunk Formula Method works
The Trunk Formula Method is the standard appraisal approach for established ornamental trees that are too large to replace with nursery stock. It starts by calculating the cross-sectional area of the trunk at breast height (4.5 ft / 1.37 m above ground): area = pi x (DBH / 2)^2. That area is multiplied by a replacement cost per square inch - this calculator uses the ISA benchmark of $50/in^2, which approximates the installed cost of nursery-grade replacement stock scaled up to the subject tree's size. The product (basic value) is then adjusted by three percentage ratings: species rating (how well-suited and desirable the species is for the locale), condition rating (structural integrity, health, and life expectancy), and location rating (how much the site enhances or diminishes the tree's contribution). Final value = Basic value x Species% x Condition% x Location%.
How timber stumpage value is calculated
Stumpage is the value of standing timber at the stump before harvesting costs are deducted. This calculator uses the Doyle log rule, the most common scaling standard in the eastern United States, to estimate board-foot volume: BF per 16-ft log = ((DBH - 4) / 2)^2 x (log length / 16). That volume is then multiplied by an estimated stumpage price per thousand board feet (MBF), which varies by species quality tier. Premium hardwoods such as Black Walnut and Teak command around $500/MBF, while commodity softwoods like White Pine may fetch only $60/MBF. Note that the Doyle rule tends to underscale smaller logs (under 20 inches DBH) and is conservative overall, so actual value may be higher if logs are large and straight.
Condition and location ratings guide
Condition rating reflects the physical health, structure, and remaining useful life of the tree. A rating of 100% represents a perfect specimen with no defects, disease, or structural weaknesses. Most mature urban trees score between 60% and 85%. Ratings below 50% indicate significant decline, decay, or structural hazard. Location rating captures the spatial and aesthetic contribution of the tree's position: a large oak anchoring the front lawn of a high-value urban property might rate 90%, while the same tree at the edge of a rural field might rate 40%. Both ratings are multiplied together in the CTLA formula, so a 70% condition tree in a 70% location receives only 49% of its basic species-adjusted value.
Species Ratings and Timber Tiers
| Species | CTLA Rating | Timber Tier | Stumpage ($/MBF est.) |
|---|---|---|---|
| Black Walnut | 95% | Premium | $500 |
| White Oak | 85% | High | $280 |
| Red Oak | 80% | High | $280 |
| Sugar Maple | 85% | High | $280 |
| Black Cherry | 80% | High | $280 |
| White Ash | 75% | Medium | $120 |
| Hickory | 78% | Medium | $120 |
| Yellow Poplar | 65% | Medium | $120 |
| Douglas Fir | 70% | Medium | $120 |
| White Pine | 60% | Low | $60 |
| Cedar | 72% | Medium | $120 |
| Paper Birch | 60% | Low | $60 |
| Beech | 73% | Medium | $120 |
| Elm | 68% | Medium | $120 |
| Mahogany | 90% | Premium | $500 |
| Teak | 95% | Premium | $500 |
CTLA species ratings (ISA Guide for Plant Appraisal, 9th ed.) and timber stumpage tiers used in this calculator. Actual market prices vary by region and season.
Frequently asked questions
What is DBH and how do I measure it?
DBH stands for Diameter at Breast Height - the trunk diameter measured at exactly 4.5 feet (1.37 m) above the ground on the uphill side. The easiest way to measure it is to wrap a flexible tape measure around the trunk at that height to get the circumference, then divide by pi (3.14159) to get the diameter. On sloped ground, measure from the uphill side of the tree to ensure consistency.
What is the difference between ornamental value and timber value?
Ornamental (or amenity) value is what the tree is worth as a living landscape feature - the cost and effort to replace its aesthetic, ecological, and functional benefits. It is used by arborists in insurance claims, legal disputes, and municipal tree inventories. Timber (or stumpage) value is the market price of the logs at the stump - what a timber buyer would pay before the costs of felling, hauling, and milling. For most shade trees in residential settings, ornamental value is higher; for large, straight premium hardwoods in accessible locations, timber value may dominate.
How accurate is this calculator?
This tool provides a reasoned planning estimate based on published ISA methodology and regional stumpage averages. Actual appraised values depend on local replacement nursery costs (which vary widely), current timber market prices, site-specific conditions, and the judgment of a qualified arborist. For insurance, legal, or tax purposes, obtain a formal appraisal from an ISA Certified Arborist or a licensed timber cruiser.
Why does the Doyle rule underestimate small trees?
The Doyle log rule was designed for large sawmill logs and becomes increasingly conservative as log diameter decreases. For trees under about 16 inches DBH, Doyle significantly underestimates recoverable board footage compared to the Scribner or International 1/4-inch rules. As a result, the timber stumpage values shown for smaller trees are conservative - actual recovery could be 20-40% higher if scaled with the International rule.
What species rating should I use if my species is not listed?
Choose the species with the closest ecological and market profile to your tree. For native hardwoods of good form and regional desirability, 75-85% is a reasonable starting point. For common but less prized species, use 60-70%. If the species is invasive, structurally weak, or very short-lived, rates below 60% are appropriate. A local ISA Certified Arborist will have the most accurate rating for your region.
Can I use this to value a tree after it has been damaged or removed?
Yes. Entering a low condition rating (10-30%) will reflect the diminished value of a severely damaged tree. For a removed tree, use the last known measurements and set condition to 0-20% if structural damage was the cause of removal. Courts and insurance adjusters often use retrospective appraisals based on photographs and neighbor records when the tree itself is gone.