Log Weight Calculator
Estimate log weight from diameter, length, species density, moisture content, taper allowance, and quantity.
Estimate log weight before cutting, hauling, milling, or stacking
A log weight calculator estimates the weight of a log by using wood species, log diameter, log length, and wood moisture content. Calculate log volume first, then multiply by wood density. This page also adjusts for taper allowance and quantity.
Green hardwood logs often weigh 50 to 75 pounds per cubic foot, while softwood logs typically weigh 25 to 50 pounds per cubic foot. Green logs can be much heavier than air-dried logs because water adds mass.
Use the result for preliminary lifting, trailer payload, firewood, sawmill, forestry, and delivery planning. Confirm actual species, moisture, bark, mud, defects, equipment rating, and legal road limits before moving logs.
Estimated total log weight
Per log --, adjusted density --
Weight per log
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Total load
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Volume
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Cost estimate
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Adjusted density
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Taper reduction
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Board-foot estimate
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Firewood cord estimate
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Log weight breakdown
Shows how size, species density, moisture, taper, and quantity affect the result.
| Step | Value | Meaning |
|---|---|---|
| Run the calculator to see the log weight breakdown. | ||
How to use the log weight calculator
- Measure diameter: Use the average diameter, or measure near the middle of the log when taper is visible.
- Enter log length: Use the length of one log, then enter the number of logs in the quantity field.
- Select species: Choose the closest species or enter a custom density if your supplier, forestry table, or scale ticket provides one.
- Set moisture: Green logs are heavier than dry logs, so use a moisture condition that matches the material.
- Add taper or defect allowance: Reduce volume for tapered logs, rot pockets, hollow sections, missing bark, or irregular shapes.
Log weight formula
Log weight is estimated from cylindrical volume and adjusted density. Diameter and length are converted to meters, volume is reduced for taper or defects, and density is adjusted for moisture content.
Volume = pi x (diameter / 2)^2 x length
Adjusted density = base density x moisture factor
Weight = volume x adjusted density x quantity
Example: an 18-inch diameter, 8-foot oak log at green moisture with a 10% taper allowance weighs about 829 pounds. The actual scale weight can vary with species, moisture, bark, knots, rot, and stem shape.
Wood density and moisture reference: USDA Forest Products Laboratory - Wood Handbook.
Typical wood density and log weight factors
Wood density varies by species, growth conditions, heartwood, sapwood, moisture, and defects. Use these values as rough planning inputs, then replace them with local data when available.
| Species | Approx. base density | Planning note |
|---|---|---|
| Oak | 705 kg/m3 | Dense hardwood; green logs are heavy and often need equipment. |
| Maple | 630 kg/m3 | Moderately heavy hardwood, especially when freshly cut. |
| Pine | 420 kg/m3 | Lighter softwood, but moisture can still make large logs difficult to move. |
| Cedar | 370 kg/m3 | Usually lighter than many hardwoods, useful for rough hauling estimates. |
| Hickory | 755 kg/m3 | Very dense hardwood; use conservative lifting and trailer assumptions. |
Moisture, taper, and hauling checks
Moisture content and taper are the two biggest practical reasons a log can weigh more or less than expected. A freshly cut log can hold a large amount of water, while a tapered or hollow log has less solid wood than a perfect cylinder.
Green vs dry logs
Use green moisture for fresh timber, storm cleanup, sawmill deliveries, and logs that have not seasoned.
Taper allowance
A 5% to 15% allowance is a reasonable starting point for many tapered logs when using a simple cylinder model.
Payload planning
Compare total weight with trailer payload, loader rating, axle limits, tie-down capacity, and safe handling procedures.
When a load is close to a vehicle or equipment limit, get an actual scale weight. This calculator is for planning, not for certifying legal or safe hauling loads.
How to measure tapered or irregular logs
The calculator assumes a simple round log, but real stems are tapered, oval, crooked, or partly hollow. Better measurements make the estimate more useful before loading a trailer or quoting a job.
Use an average diameter
Measure both ends and average them, or measure near the midpoint. For oval logs, measure the wide and narrow directions and average those too.
Separate mixed logs
Do not average a pile of very different logs into one diameter. Group similar logs by species, size, and moisture, then run the calculator for each group.
Account for missing wood
Increase taper or defect allowance when logs have rot, hollow centers, split ends, slabbed sides, large branch pockets, or missing chunks.
Keep bark and mud in mind
The estimate is for wood volume. Thick bark, mud, ice, and attached limbs can add hauling weight even when they do not add useful lumber volume.
Log scaling and measurement reference: University of Tennessee Extension - Understanding Log Scales and Log Rules.
Common log weight examples
These examples use the same model as the calculator: green moisture, 10% taper allowance, and the listed species density. Use them as a quick reality check before entering your own measurements.
| Example log | Diameter x length | Approx. green weight | Planning takeaway |
|---|---|---|---|
| Pine | 12 in x 8 ft | About 219 lb | Small softwood logs may still need two-person handling. |
| Oak | 18 in x 8 ft | About 829 lb | A single hardwood log can approach compact trailer payload limits. |
| Maple | 24 in x 10 ft | About 1,646 lb | Equipment and securement planning become important. |
| Hickory | 30 in x 12 ft | About 3,698 lb | Dense hardwood loads can exceed many small trailer ratings. |
| Cedar | 16 in x 10 ft | About 430 lb | Lighter species are easier to handle, but length can still be awkward. |
Load planning checklist for logs
A weight estimate is only one part of a safe log move. Before hauling or lifting, compare the calculated load with the whole system, not just the trailer sticker.
Vehicle and trailer
Check payload, axle ratings, tongue weight, tire load rating, hitch rating, and braking capacity, then include chains, bunks, ramps, and tools.
Loading equipment
Compare the heaviest single log with winch, loader, tractor, grapple, fork, and rigging ratings. Watch for side loading and uneven ground.
Securement
Logs can roll, shift, or slide. Use appropriate bunks, chocks, binders, straps, chains, and legal tie-down practices for the route.
If a calculated load is close to a limit, reduce the load or get a certified scale weight. A wet or muddy log can erase the margin you thought you had.
Cargo securement reference: Federal Motor Carrier Safety Administration - Cargo Securement Rules.
Interesting fact
A freshly cut log can contain more water weight than wood substance. USDA Forest Products Laboratory references show green wood moisture content can range from about 30% to more than 200%, depending on species and whether heartwood or sapwood is measured. That is why the same diameter and length can produce very different hauling weights after drying. Source: USDA Forest Products Laboratory - Wood Handbook.
Frequently Asked Questions
What is a log weight calculator used for?
A log weight calculator estimates the weight of a round log, tree section, or timber piece by calculating volume and multiplying it by wood density. It helps with forestry work, harvest planning, firewood handling, sawmill estimates, and deciding whether a truck or trailer can safely carry the load when an actual scale weight is not available.
How do I calculate log weight from diameter and length?
Calculate log volume with the cylinder formula, volume = pi x radius squared x length, then multiply by adjusted wood density. The diameter controls the radius, the length controls the cylinder size, and the species and moisture settings determine whether the log behaves more like a dense hardwood or a lighter softwood. This calculator also applies quantity and taper allowance so the estimate better matches real logs.
Why are green hardwood and softwood logs heavier than dry logs?
Green logs contain more water in the wood cells and pores, so moisture adds directly to the load weight. As a log dries, it loses water weight, and the same cubic foot of timber can become much lighter over time. The drying rate depends on species, log diameter, bark, climate, whether the wood is hardwood or softwood, and how the firewood or lumber stock is stored.
Should I use small-end diameter or average diameter for a log?
Use average diameter for a weight estimate because weight depends on total volume, not only the small end. If you only know the small-end diameter from a sawmill or forestry scale, reduce confidence in the result or use a taper allowance that reflects the tree shape. For a noticeably tapered harvest log, measuring both ends gives a better estimate than using one diameter alone.
Is board foot, cord, or cubic foot volume the same as log weight?
No. A board foot estimates lumber volume, a cord estimates stacked firewood volume, and a cubic foot measures solid or bulk volume depending on the context. Log weight estimates mass, so it depends on wood density, moisture, species, and total load size. A heavy green log may not produce more lumber than a lighter dry log of the same size, and sawmill recovery depends on taper, defects, saw kerf, grade, and milling method.
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Disclaimer: This log weight calculator is for general educational, forestry, firewood, hauling, milling, landscaping, and material planning use only. It estimates log weight from user-entered diameter, length, units, species density, moisture content, taper allowance, quantity, and optional price per ton. It does not replace certified scale tickets, forestry cruising, timber appraisal, sawmill grading, structural engineering, equipment manuals, load securement rules, road weight regulations, or professional judgment. Actual log weight can vary because of species variation, heartwood and sapwood proportion, bark thickness, knots, rot, hollows, cracks, mud, ice, embedded metal, moisture gradient, shrinkage, taper, oval stems, measurement error, density table uncertainty, and handling conditions. Confirm load weight, equipment capacity, trailer payload, axle limits, legal requirements, lifting method, and site safety before cutting, lifting, hauling, selling, or purchasing logs.
Last updated: June 9, 2026