Log Weight Calculator
This log weight calculator or wood weight calculator will help you estimate the weight of a log or board made of any of the common species of wood at any desired length and cross-sectional dimensions.
In this calculator, you will learn to answer the question of "How much does a log weigh?" and what affects the weight of wood. You will learn about the wood density chart, also known as the "green" log weight chart, as well as Huber's Formula to determine the volume of a log. Keep on reading to start learning how to calculate the weight of a log.
Weight of wood and the wood density chart
The weight of wood mainly depends on three factors: the wood species, the volume of the log, and its moisture content. The wood species tells us the density of the wood. However, the density of the wood varies depending on its moisture content.
The moisture content of wood is the amount of water within the wood. It ranges between 150% or more for fresh wood and as low as 5% for processed and dried wood. For wood, we determine its moisture content by taking the percentage of the water's weight in freshly-cut wood to the same wood's oven-dry weight. A 250-kg freshly-cut wood weighing 100 kg after oven-drying would have a moisture content of 150%. The higher the moisture content is, the heavier the wood weighs. In this calculator, we consider the "green" density of wood, which is the density of a piece of freshly cut wood.
The green density varies from tree to tree and does not pertain to a particular moisture content for each tree species. As a reference, you can check the wood density chart below, which is also sometimes called the green log weight chart, for the green density of the most common tree species found on the market today:
|Alder, red||Magnolia ev.|
|Ash, green||Maple, silver|
|Ash, Oregon||Maple, sugar|
|Ash, white||Oak, black|
|Aspen, quaking||Oak, Cali. black|
|Bald cypress||Oak, English|
|Birch, paper||Oak, post|
|Birch, yellow||Oak, red|
|Cedar, incense||Oak, white|
|Cedar, western red||Osage orange|
|Elm, American||Pine, longleaf|
|Fir, Douglas||Pine, ponderosa|
|Fir, noble||Pine, slash|
|Fir, white||Pine, sugar|
|Gum, black||Pine, white|
|Gum, red||Poplar, yellow|
|Hemlock western||Spruce, Red|
|Hickory Shagbark||Spruce, sitka|
|Locust, black||Walnut, black|
Even though it shows the density, this is also known as the green log weight chart because it instantly shows us the green weight of wood per cubic foot of volume.
How much does a log weigh? - Huber's formula
Knowing the green density of the tree species we are considering is the first step towards answering "How to calculate the weight of a log?". In the next step, we have to multiply this density by the log's volume to obtain its weight. This is expressed as an equation below:
weight = ρgreen * v
weight- Weight of the log in pounds;
ρgreen- "Green" weight of the wood per cubic foot (lb/ft3); and
v- Volume of the log in cubic feet.
For this wood weight calculator, we use Huber's formula to determine a log's volume. In Huber's formula, we first need to find the log's diameter at the center of the entire log's length. We can do this either by directly measuring the diameter at the middle of the log or by getting the average of the diameters on both ends of the log.
Due to the nature of a tree, the log's diameter near the top end of the tree is smaller than the log's diameter towards the base (or roots). Keeping these concepts in mind, we now have Huber's log volume formula:
v = L * (π *
dm2 / 4)
v- Volume of the log in cubic feet;
L- Length of the log; and
dm- Diameter at the mid-section of the log which is equal to
(ds + dl) / 2, where:
ds- Diameter at the smaller end of the log; and
dl- Diameter at the larger end of the log.
Using our log weight calculator
Determining the weight of wood in the shape of a log or board is made easy using our log weight calculator. Here are the instructions on how to use our calculator:
- Choose the shape of wood you have - either a log or board.
- Select the tree species that you are considering from the drop-down selection in the "Species" field. Choosing a species locks in the density value of your wood. You can view the weight of wood per cubic foot value in our calculator's
advanced modeif you want to check or change it.
- Input the dimensions of your wooden log or board. Entering these values automatically finds the volume of the wood. At this time, the weight per piece of log or board will also be already displayed.
- If you have multiple wood quantities with the same dimensions, enter their quantity to calculate their total weight.
The importance of knowing how to calculate the weight of a log
As with other materials in construction, knowing the weight of a material aids in logistical considerations and in assessing whether or not equipment can carry the load.
Since we cannot always have a weighing scale around us, knowing how to calculate the weight of a log using the measurements we can find on site, whether with the help of our wood weight calculator or through manual calculations, can sometimes save the day.
Want to learn more?
If you're splitting your wood for firewood and would like to know how much you've got, you might perhaps find our cord of wood calculator interesting and useful.