Log Weight Calculator
Estimate the weight of round logs from diameter, length, wood density, and quantity. Get total weight in pounds, kilograms, and US tons.
Calculate Log Weight
Weight Estimate
Weight = π × (Diameter ÷ 2)² × Length × Density
What Is a Log Weight Calculator?
A Log Weight Calculator estimates the weight of a round log using its diameter, length, and an assumed wood density. It treats the log as a cylinder to calculate approximate volume before converting that volume into weight.
The result is useful for forestry planning, transport estimates, woodworking, firewood handling, and equipment load checks. Real logs are irregular, so the calculated result should be treated as an estimate rather than an exact scale weight.
Log Volume
Estimate cylindrical log volume from diameter and length.
Log Weight
Convert volume into estimated weight using wood density.
Total Load
Multiply by the number of logs to estimate a combined load.
How the Log Weight Calculator Works
The calculator first converts your measurements to feet. It then calculates the volume of a cylindrical log and multiplies that volume by the selected wood density.
- Enter the average log diameter.
- Enter the log length.
- Select a wood species or enter a custom density.
- Enter the number of logs.
- Select an optional moisture adjustment.
- Click Calculate Weight.
Log Weight Formula
Radius = Diameter ÷ 2
Volume = π × Radius² × Length
Weight = Volume × Wood Density
Total Weight = Weight Per Log × Number of Logs
Log Weight Calculation Example
Suppose an approximately cylindrical oak log is 12 inches in diameter and 8 feet long. A 12-inch diameter equals 1 foot, giving a radius of 0.5 feet.
The cylindrical volume is about 6.28 cubic feet. Using an example density of 45 lb/ft³ gives an estimated base weight of about 283 pounds before any optional moisture adjustment.
Example Wood Density Values
| Wood Type | Example Density | Calculator Use |
|---|---|---|
| Oak | 45 lb/ft³ | Dense hardwood estimate |
| Maple | 44 lb/ft³ | Hardwood estimate |
| Birch | 42 lb/ft³ | Hardwood estimate |
| Walnut | 38 lb/ft³ | Medium-density hardwood estimate |
| Pine | 32 lb/ft³ | Softwood estimate |
| Spruce | 28 lb/ft³ | Lighter softwood estimate |
| Cedar | 23 lb/ft³ | Light softwood estimate |
These values are simplified planning inputs, not fixed physical constants. Wood density changes with exact species, moisture content, age, and growing conditions.
Tips for Better Log Weight Estimates
- Measure diameter at more than one point when the log tapers.
- Use the average diameter for an irregular log.
- Use a density value that matches the actual species when possible.
- Remember that green or wet wood can be substantially heavier than dry wood.
- For lifting or transport safety, verify heavy loads with suitable weighing equipment.
Log Weight Calculator FAQs
How do I calculate the weight of a log?
Estimate the log volume from its diameter and length, then multiply the volume by the wood density. This calculator performs those conversions automatically.
Why does wood species affect log weight?
Different species have different densities. A dense hardwood log can weigh much more than a softwood log of the same dimensions.
Does moisture affect log weight?
Yes. Water adds significant mass to wood. Freshly cut or wet logs may be much heavier than seasoned or kiln-dried logs.
Can I enter a custom wood density?
Yes. Select Custom Density and enter either pounds per cubic foot or kilograms per cubic meter.
Can I calculate multiple logs?
Yes. Enter the number of similarly sized logs and the calculator will show both per-log weight and combined weight.
Is the calculated weight exact?
No. Logs taper and vary in moisture, shape, bark, and density. The calculator is intended for practical estimates rather than certified weighing.