How Many Board Feet in a Tree? Log Board Foot Calculator (Doyle Log Scale)

Georgette Kilgore headshot, wearing 8 Billion Trees shirt with forest in the background.Written by Georgette Kilgore

Carbon Ecological Footprint Calculators | March 28, 2024

Man looking at boards of lumber at his feet and a tree on his right wonders about how to calculate for how many board feet in a tree.

What exactly is a board foot, and how do you determine how many board feet in a tree?

A board foot is the unit of measurement used for the volume of lumber in the US as well as Canada. It’s used in all sorts of construction projects, from furniture building to structural design, as well as for calculating how much a tree is worth from a material standpoint.

But, before you can figure this amount, you need to know which system you’ll use.

Try this log Board Foot Calculator right now to see how man board feet in a tree…any tree.

What is a Board Foot Calculator?

A board foot calculator used a specific method, such as the Doyle Log Scale, to determine how much salable wood is in a tree.

One board foot is equal to the volume of a 305mm length of board that is 1 foot wide and 25.4mm (1 inch) thick.

One thousand board feet is referred to as MBF.

The following are equal to 1 board foot:

  • 1 foot x 1 foot x 1 inch
  • 12 inch x 12 inch x 1 inch
  • 144 in3
  • 1/12 ft3
  • ≈ 2,360 cubic cm
  • ≈ 2.36 liters
  • ≈ 0.00236 cubic meters/steres
  • 1/1980 Petrograd Standard

A board foot is instrumental in measuring rough lumber, before the lumber is dry and before planing is done. Planed and surfaced lumber is also measured using the board foot.

Related Reading: How Many Trees Cut Down Each Year or in 2022? The Deforestation Crisis Explained

Tree Dimensions

Tree dimensions are established through tree volume estimation, and measuring tree diameter as well as measuring merchantable height.

Estimating tree volume is done by immersing cut logs or entire trees in a large tank filled with water, and then measuring the displaced volume of water.

Pile of woods in the ground with trees behind.

Image: Ibrahim Rifath9

Naturally, this process takes a lot of time and effort, which is why woodworkers and foresters use different, indirect methods to estimate tree volumes. These methods include using diameter at breast height (DBH) and height, as well as a volume table with a volume equation.

A great tool, called a Biltmore stick, is often used to measure tree diameters.

How Much Lumber in a Tree?

When determining how much lumber in a tree, the following Biltmore rule graduations must be considered:

Diameter Graduations on a stick Distance in Inches From the End of Stick to Diameter Graduations Diameter-Graduations on Stick Distance in Inches From End of Stick to Diameter Graduations
5 4.6 18 13.7
6 5.4 19 14.3
7 6.2 20 14.9
8 7.0 21 15.5
9 7.7 22 16.0
10 8.0 23 16.6
11 9.2 24 17.1
12 9.8 25 17.7
13 10.5 26 18.2
14 11.2 27 18.7
15 11.8 28 19.2
16 12.5 29 19.7
17 13.1 30 20.2

The tree diameter should be measured as follows:

  • The Biltmore stick should be held at eye level, 25 inches away, in a horizontal position.
  • The beveled edge of the stick should be held against the tree trunk at breast height.
  • The zero ends of the stick must be lined up with the left side of the tree.
  • The line of sight should be moved to the right side of the tree, without moving the head, and the diameter that comes into the line of sight should be read.

The diameter of a tree can also be measured by wrapping a tape measure around the circumference of the tree. The tape measure should be at 4.5 feet above the base of the tree and the circumference should be divided by 3.14 π, to calculate the tree’s diameter.

Photo that shows the diagram on how one can get a board from a trump.

When measuring the height of a tree, units of 16-foot logs or fractions are used. When a tree is straight and slim, the measurement stretches to a point on the upper trunk where the diameter measures eight inches inside the bark.

Older trees should be measured between the height of the stump and the remaining usable height of the tree, minus excess branches.

The Merritt rule for measuring tree heights can be inscribed on the Biltmore stick by marking graduations of 6.1 inches from the zero sides of the stick.

Every graduation represents a 16-foot log (in length). The half-log marks should be inscribed halfway in between the 16-foot-long marks, and the following method should be used for measuring.

Photo that shows how you can measure the diameter of a tree

  • Stand at least 66 feet away from the tree base, and raise the stick vertically 25 inches from eye level.
  • The stick’s zero ends should be in the line of sight with the maximum limit of usable height.
  • The line of sight should be shifted to stump height at the tree base, which is generally between twelve and sixteen inches above ground level. The scale should be used to read the number of logs, or fractions, related to the tree.

Determining Tree Volume

Determining tree volume follows the measuring of the height and diameter of the trees. The board foot content for each relevant tree is read from a volume table and board foot volume can be calculated in different ways.

Photo of a pile of fire woods beside a swamp.

Image: Ales Krivec11

The below table indicates the board foot values when trees are personally felled and the logs transported to the mill (international rule applies):1

Diameter 4 ½ feet above the ground (inches) Number of 16-foot logs

 
1 2 3 4
Volume in board feet
Diameter: 10 35 60
Diameter: 11 45 Volume: 75
Diameter: 12 Volume: 55 Volume: 90 Volume: 120
Diameter: 13 Volume: 65 Volume: 110 Volume: 145
Diameter: 14 Volume: 80 Volume: 130 Volume: 175
Diameter: 15 Volume: 90 Volume: 155 Volume: 200
Diameter: 16 Volume: 180 Volume: 240 Volume: 285
Diameter: 17 Volume: 205 Volume: 280 Volume: 330
Diameter: 18 Volume: 235 Volume: 315 Volume: 375
Diameter: 19 Volume: 265 Volume: 360 Volume: 425
Diameter: 20 Volume: 295 Volume: 400 Volume: 480
Diameter: 21 Volume: 330 Volume: 450 Volume: 540
Diameter: 22 Volume: 370 Volume: 500 Volume: 605
Diameter: 23 Volume: 405 Volume: 550 Volume: 665
Diameter: 24 Volume: 440 Volume: 605 Volume: 725
Diameter: 25 Volume: 485 Volume: 665 Volume: 800
Diameter: 26 Volume: 725 Volume: 880
Diameter: 27 Volume: 790 Volume: 950
Diameter: 28 Volume: 850 Volume: 1,030
Diameter: 29 Volume: 920 Volume: 1,110
Diameter: 30 Volume: 990 Volume: 1,070

The next table is applicable to selling standing trees in the Lower Peninsula (Doyle rule applies):

Diameter 4 ½ feet above the ground (inches) Number of 16-foot logs

 
1 2 3 4
Volume in board feet
Diameter: 10 Volume: 15 Volume:20
Diameter: 11 Volume:20 Volume:30
Diameter: 12 Volume:30 Volume:45 Volume:50
Diameter: 13 Volume:40 Volume:60 Volume:70
Diameter: 14 Volume:50 Volume:75 Volume:95
Diameter: 15 Volume:60 Volume:95 Volume:120
Diameter: 16 Volume:115 Volume:150 Volume:170
Diameter: 17 Volume:140 Volume:180 Volume:210
Diameter: 18 Volume:165 Volume:215 Volume:250
Diameter: 19 Volume:195 Volume:255 Volume:300
Diameter: 20 Volume:225 Volume:295 Volume:350
Diameter: 21 Volume:260 Volume:345 Volume:400
Diameter: 22 Volume:295 Volume:390 Volume:460
Diameter: 23 Volume:330 Volume:445 Volume:520
Diameter: 24 Volume:370 Volume:495 Volume:580
Diameter: 25 Volume:415 Volume:560 Volume:660
Diameter: 26 Volume:620 Volume:740
Diameter: 27 Volume:685 Volume:815
Diameter: 28 Volume:750 Volume:890
Diameter: 29 Volume:825 Volume:980
Diameter: 30 Volume:900 Volume:1,070

The next table applies to trees that are in the Upper Peninsula (Scribner Decimal C rule):

Diameter 4 ½ feet above ground (inches) Number of 16-foot logs

 
1 2 3 4
Volume in board feet
Diameter: 10 Volume: 3 Volume: 4
Diameter: 11 Volume: 4 Volume: 6
Diameter: 12 Volume: 5 Volume: 8 Volume: 10
Diameter: 13 Volume: 6 Volume: 9 Volume: 12
Diameter: 14 Volume: 7 Volume: 11 Volume: 15
Diameter: 15 Volume: 8 Volume: 14 Volume: 18
Diameter: 16 Volume: 16 Volume: 21 Volume: 25
Diameter: 17 Volume: 18 Volume: 25 Volume: 29
Diameter: 18 Volume: 21 Volume: 28 Volume: 33
Diameter: 19 Volume: 24 Volume: 32 Volume: 38
Diameter: 20 Volume: 27 Volume: 36 Volume: 43
Diameter: 21 Volume: 30 Volume: 41 Volume: 49
Diameter: 22 Volume: 34 Volume: 46 Volume: 55
Diameter: 23 Volume: 37 Volume: 51 Volume: 61
Diameter: 24 Volume: 41 Volume: 56 Volume: 66
Diameter: 25 Volume: 45 Volume: 62 Volume: 74
Diameter: 26 Volume: 68 Volume: 81
Diameter: 27 Volume: 74 Volume: 89
Diameter: 28 Volume: 80 Volume: 96
Diameter: 29 Volume: 86 Volume: 104
Diameter: 30 Volume: 93 Volume: 112

It must be noted that when these volume tables are used, the volume figures must be increased by 10% when the following tree types are measured:

Related Reading: How Many Trees Are in the World? By Country, Type, Year (Updated 2022)

Doyle Scale

The Doyle scale refers to the standard adhered to when hardwood lumber is traded (bought and sold) The Doyle scale is highly effective in estimating large and medium logs almost to the exact number, but it does underestimate smaller logs.2

Doyle Log Scale

The Doyle log scale as well as the Doyle Log Rule was created in 1825, as a math formula used to determine board feet in any given tree.

The Doyle Log Rule permits a 5/16” saw kerb allowance and allotment of 4” for slab-cutting purposes.

The Scribner Log Rule was created in 1846 and refers to the rule of diagrams, the process of which involves drawing simple cross-sections of one-inch boards inside circles that indicate the view from the end of any given log.

A gap of a quarter inch is left in the middle of the boards. This is for saw kerf purposes (the cut that accumulates pulp from the tree as it saws).

The Scribner Decimal C rule differs from the Scribner rule, in that it rounds off the volumes to the closest 10 board feet.

The international quarter-inch log rule was the latest addition to the mix, created in 1906.

The rule includes a quarter of an inch when it comes to saw kerf (which is the size of the most common blades), as well as a predetermined tapering allotment of half an inch for every 4 ft.3

Doyle Log Calculator

The Doyle log scale in board feet is as follows:4

Log Length (Feet)
Diameter (Small end in inches) 8 inches 10 inches 12 inches 14 inches 16 inches 18 inches 20 inches
8 inches 8 10 12 14 16 18 20
10 inches 18 23 27 32 36 41 45
12 inches 32 40 48 56 64 72 80
14 inches 50 63 75 88 100 113 125
16 inches 72 90 108 126 144 162 180
18 inches 98 123 147 172 196 221 245
20 inches 128 160 192 224 256 288 320
22 inches 162 203 243 284 324 365 405
24 inches 200 250 300 350 400 450 500
26 inches 242 303 363 424 484 545 605
28 inches 288 360 432 504 576 648 720
30 inches 338 423 507 592 676 761 845
32 inches 392 490 588 686 784 882 980
34 inches 450 563 675 788 900 1013 1125
36 inches 512 640 768 896 1024 1152 1280
Diameter refers to the distance across the small cut end of the log and is measured over the shortest distance inside the bark.

A Doyle log calculator provides a simple estimate for board feet.

The inputs required are as follows:

  • Length of log (feet)
  • Diameter of log (measure via small end in inches (inside bark)

This will then calculate the number of board feet.5

Board Feet in a Log Calculator

A board feet in a log calculator, also referred to as a board foot log rule calculator, estimates the board foot yield of any given log with the Scribner or Doyle log scale rules or the International log rule.

This calculator is also used to estimate the board-foot yield of standing trees.

How To Calculate Board Feet in a Log

How to calculate board feet in a log, depends on the following calculations:

  • Diameter inside bark (breast height in inches)
  • Length of log (standing equals tree height (ft)
  • Log rule or standing tree rule:
    • Doyle
    • Scribner
    • International ¼” Kerf
    • International ⅛” Kerf
    • Doyle Standing Tree
    • Scribner Standing Tree
    • International ¼” Standing Tree

The output of these calculations is the estimated number of board feet.

Log Board Feet Calculation

Log board feet calculation can also be done using different methods such as weight log volume estimates or electronic log volume measurements.

However, log scaling methods remain the most popular, and traditional way to calculate board feet.

Log Board Foot Calculator

The log board foot calculator log rules are as follows:6

  • Doyle Rule

BF=(d−4)2(16)
L

  • Scribner Rule

BF=(.79D2−2D−4)

  • ¼” Kerf Log Rule

BF=0.055000LD2 + 0.006875L2D

−0.205000LD + 0.00028645833L3

−0.201281250L2  + 0.04666667L

  • ⅛” Kerf Log Rule

BF=0.04976191LD2 + 0.006220239L2D

−0.1854762LD + 0.000259176L3

−0.01159226L2 + 0.04222222L

How To Calculate MBF of Timber

How to calculate MBF of timber requires the following steps:

  1. Define the base volume for a board foot. (volume is defined as 12x12x1 which equals 144 cubic inches)
  2. Convert cubic inches to cubic meters: (0.0254) ^3 = 0.0000164 cubic meters in a cubic inch.
  3. Convert base volume for BF into cubic meters: 255 x 0.0000164 equals 0.00236 cubic meters in a board foot.
  4. Use the board foot as a unit of measure for lumber that remains not planed, and not dried.
  5. Convert the board foot measure to the actual volume of planned lumber. This is done by reducing each linear dimension of lumber by one-quarter-inch for 2 inches and less, one-half-inch for 8 inches and less, and three-quarter-inch for 8 inches and more. The resulting measures should be multiplied to calculate the volume of planned lumber.7

Board Feet Calculator for Standing Trees

The board feet calculator for standing trees requires the following inputs:

  • Description
  • Taper Factor
  • Diameter at breast height
  • Height in feet8

How Many Board Feet in a Tree?

When determining how many board feet in a tree, the average board feet per tree should be noted.

What’s the Average Board Feet Per Tree?

The average board feet per mature tree is between 250 and 500.

How Many Board Feet in a Tree?

How many board feet in a tree calculations also include the question, how many 2×4 are in a tree?

How Many 2×4 in a Tree?

So, how many 2×4 in a tree?

There are approximately 19.2 2x4s in every tree. But, this number is drastically impacted by the size of the tree and the species.

Carbon Footprint of Building Materials

The carbon footprint of common building materials is as follows:

  • Rammed earth – 48 kg of embodied CO2 per M3.
  • Softwood timber – 110 kg of embodied CO2 per M3
  • Cross-laminated timber – 219 kg of embodied CO2 per M3
  • Stone – 237 kg of embodied CO2 per M3
  • Clay brick – 345 kg of embodied CO2 per M3
  • Reinforced concrete – 635 kg of embodied CO2 per M3
  • Glass – 3600 kg of embodied CO2 per M3
  • Steel – 12090 kg of embodied carbon per M3
  • Aluminum – 18009 kg of embodied carbon per M3

How Many Trees Does It Take To Build a House?

In the US, the average board feet of lumber to build a 2,600 square-foot home in 2013, was 16,380. This equals around 22 mature fir trees. However, the count does not end there, as another estimated 24 trees will be required for finishes such as roofing, flooring, and cabinetry.

Photo of a house constructed using woods.

Image: Sandy Millar10

All in all, it requires more than 20 mature Douglas Fir trees to construct 1,000 square feet of a house.

When determining how many trees does it take to build a house, and how many board feet in a tree, it is important to remember the impact of this type of construction on the environment, and that tree planting carbon offsets, like Climate Plus Program Green Construction can be used to erase those emissions, and replace the building materials used.

Frequently Asked Questions About How Many Board Feet in a Tree

How Many Board Feet in a Tree?

The average board feet per tree is between 250 and 500.

How Do You Measure the Board Feet in a Log?

Estimating the board feet in a log, requires the measuring of the average diameter of the smaller part of the log (inches), and measuring the length of the log (feet). The log scale should be moved to the point where these two measurements meet, which will provide the board foot output.

What Info Does a Log Board Feet Calculator Include?

A log board feet calculator requires the following inputs:

  • Diameter in inches or fractions
  • Length in feet and inches
  • Number of logs
  • Log scale (Doyle, Scribner, International)

How Does a Board Foot Calculator Log Work?

Board foot calculator log calculations are estimated using several inputs based on Doyle, Scribner, or International log rules.

What’s the Ikea Tiny House?

The Ikea Tiny House follows the ‘tiny home’ trend, but in a sustainable fashion, as it is eco-friendly.

What’s the Carbon Footprint of Timber?

One kilogram of timber produces up to 1.80 kg of CO2 emissions.

Read More About How Many Board Feet in a Tree

References

1Peterson, G. (2015, November 16). How Much Lumber in that Tree? How Much Lumber in that Tree? (E2915). Retrieved December 11, 2022, from <https://www.canr.msu.edu/resources/how_much_lumber_in_that_tree_e2915>

2Alabama Sawyer. (2022). How Much Wood Will My Log Yield | Doyle Scale Calculator. Alabama Sawyer. Retrieved December 11, 2022, from <https://alasaw.com/pages/how-much-wood-will-my-log-yield-doyle-scale-calculator>

3Global Timber. (2022). Doyle Scale. Global Timber. Retrieved December 11, 2022, from <https://www.globaltimberinc.com/doyle-scale.html>

4Horigan Urban Forest Products. (2022). Doyle Log Scale in Board Feet. Horigan Urban Forest Products. Retrieved December 11, 2022, from <https://horiganufp.com/wp-content/uploads/2022/03/doyle-log-scale-2022.pdf>

5Spike’s Calculators. (2022). Doyle Log Rule Calculator. Spike’s Calculators. Retrieved December 11, 2022, from <https://www.spikevm.com/calculators/logging/doyle-log-scale.php>

6DQYDJ. (2022). Log Rule Board Feet Calculator. DQYDJ. Retrieved December 11, 2022, from <https://dqydj.com/log-rule-board-feet-calculator/>

7Robinson, A. (2022). How to Calculate MBF of Lumber. Hunker. Retrieved December 11, 2022, from <https://www.hunker.com/13401549/how-to-calculate-mbf-of-lumber>

8RD Concepts. (2022). Online Board Feet Calculator for Standing Trees. RD Concepts. Retrieved December 11, 2022, from <http://www.rdconcepts.net/StandingTree.aspx>

9Tree log Photo by Ibrahim Rifath. Unsplash. Retrieved from <https://unsplash.com/photos/pPftEflZH-U>

10a building under construction with scaffolding around it Photo by Sandy Millar. Unsplash. Retrieved from <https://unsplash.com/photos/u1KG_wZTnkg>

11Firewood on river photo by Ales Krivec. Unsplash. Retrieved from <https://unsplash.com/photos/KnV-mJDGWzU>