Tree Volume Calculator

A standing tree is not a cylinder, but its wood volume can be estimated surprisingly well from just two field measurements: the diameter at breast height (DBH) and the total height. Foresters combine those two numbers with a form factor that corrects for the natural taper of the trunk, and the calculator below does that math at once, reporting the volume in cubic meters, cubic feet, board feet, and cords so the same answer works whether you sell timber, stack firewood, or simply want to know what is standing in your yard.

Quick Answer

How to use this calculator

Start with the unit toggle. Metric takes DBH in centimeters and height in meters; imperial takes DBH in inches and height in feet. The math is identical in both modes because every input is converted to meters before the formula runs, so switching units after entering numbers does not rescale the numbers you typed: re-enter them in the new unit. Then pick the species group closest to your tree and click Calculate tree volume. Results stay hidden until you calculate, and Reset clears the inputs and the result.

The formula, and why a form factor is in it

The tool treats the trunk as a cylinder and then shrinks it for taper. Volume equals pi times radius squared times height times the form factor, where radius is half the DBH. A perfect cylinder would have a form factor of 1.00, but no real trunk is a cylinder: it narrows from base to top, so the factor sits well below 1.00. That single factor carries most of the uncertainty in the answer, which is why the tool exposes it instead of burying a fixed value. Change it from 0.45 to 0.55 and the volume moves by about 22 percent, in exact proportion, because volume is directly proportional to the factor.

The conversions after the main result are fixed arithmetic. Cubic feet multiply cubic meters by 35.3147. Board feet multiply cubic meters by 423.776, which follows from one board foot being 144 cubic inches. Cords divide cubic feet by 128, since a standard stacked cord measures 4 feet by 4 feet by 8 feet. None of those three steps adds new measurement error; they only restate the same estimate in the unit a buyer or a woodpile uses.

Measuring DBH and height in the field

DBH means diameter at breast height, measured 1.3 meters (about 4.5 feet) above the ground on the uphill side of the tree. The fixed height matters: measuring lower catches the flared root zone and inflates the volume, while measuring higher catches a narrower stem and understates it. A diameter tape reads DBH directly; a normal tape gives circumference, and dividing that by pi gives the diameter. On a slope, measure from the uphill side, which is the forestry convention the 1.3 meter figure assumes.

Height is the harder measurement and usually the bigger error source. A clinometer or laser rangefinder is the reliable route. A workable phone method is to stand back a known distance, measure the angle to the top with an inclinometer app, and compute height as distance times the tangent of that angle, adding your eye height if the app does not. Enter total height to the top of the tree, not height to the first branch: the formula prices the whole stem, branches excluded, so a first-branch height understates the stem the tool is modelling.

Choosing the form factor

Use the table as a starting point, not as a species-by-species verdict. Conifers such as pines, spruces, and firs hold a fairly straight stem and average about 0.45. Typical broadleaf hardwoods such as oaks, maples, and ash taper more and average about 0.50, which is why 0.50 is the default. Fast-growing plantation trees such as poplar and eucalyptus are often near 0.55. Published form-factor work shows stem form alone can move volume by roughly 9 to 18 percent between trees of the same diameter and height, so a tree that is unusually full or unusually tapered deserves a nudge up or down from its group value, and a commercial decision deserves a professional cruise rather than a single preset.

Worked example, checked against this exact tool

Take a hardwood with DBH 50 cm and height 20 m at the 0.50 factor. Radius is 0.50 divided by 2, which is 0.25 m. Volume is pi times 0.25 squared times 20 times 0.50, which is pi times 0.0625 times 10, giving 1.963 cubic meters. Cubic feet are 1.963 times 35.3147, giving 69.34. Board feet are 1.963 times 423.776, giving 832.1. Cords are 69.34 divided by 128, giving 0.542. Run those exact inputs through the calculator and you get 1.963 cubic meters, 69.34 cubic feet, 832.1 board feet, and 0.542 cords, matching the hand calculation digit for digit.

A second check shows why DBH dominates the answer. A conifer at 30 cm DBH and 15 m height with a 0.45 factor gives 0.477 cubic meters, 16.85 cubic feet, 202.2 board feet, and 0.132 cords. Double the DBH and the volume roughly quadruples, because diameter enters the formula squared, while doubling height only doubles it. Measure DBH carefully; a sloppy diameter reading costs four times what a sloppy height reading costs.

Standing tree or felled log: pick the right tool

This page volumes a standing tree from DBH and height with a taper correction. It is not the same job as scaling a log that is already on the ground. A felled log is measured by its length and end diameters and priced by a log rule, and that is what the log volume calculator does. If your tree is already down, use that page instead of feeding a log length into this one as if it were a height.

The board-feet distinction deserves emphasis because it is where this kind of tool most often misleads. The 832.1 board feet in the worked example is the cubic volume restated in board-foot units. A Doyle or Scribner scale, the kind a sawmill uses, estimates sawn lumber yield after milling losses and kerf, and it deliberately undervalues small-diameter stems. Expect a log-scale number for the same tree to read lower, and do not treat the gap as an error in either figure: they answer different questions. The cost per board foot calculator is the next step once you have a board-foot figure and a local price.

What competing calculators miss

Most tree volume tools fall into two camps: metric-only tools that return cubic meters, and imperial-only tools that return cubic feet, each with a hard-coded taper assumption and no way to change it. The Brave Calculator version states the same tapered-cylinder formula with a fixed 0.5 factor and reports cubic meters only. The stem calculator at Calculator City explains the 0.3 to 0.7 form-factor range well but again leaves the user with a single-unit answer. Neither reports all four units a tree owner actually needs, and neither lets a conifer be estimated with anything but a hardwood taper. This page covers all four outputs from one pair of measurements, adds the imperial mode the metric-only tools lack, and exposes the form factor so the taper assumption is visible and changeable.

The honest gap in this page is the same gap every two-measurement tool has: it prices the stem only. Branches, bark thickness, hollow trunks, rot, forks, and merchantable length (how much of the stem is actually saleable) are all outside the formula. A professional timber cruise uses species-specific volume tables built from thousands of felled trees and prices by merchantable sections. Use this calculator for planning and for comparing trees, and confirm any sale with a local forester or timber buyer, who can also put a price on the result through the timber value calculator route with local rates.

Frequently asked questions

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Disclaimer: this calculator gives a planning estimate of stem volume from two measurements. It does not account for hollow trunks, rot, forks, or merchantable length, and it is not a substitute for a professional timber cruise or appraisal. Verify any commercial decision with a licensed forester.