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Wood Volume Calculator - Calculate Cubic Volume of Timber
Professional wood volume calculator for timber and lumber professionals. Calculate cubic volume using industry-standard methods including rectangular timber and round log calculations. Supports Doyle rule and International rule for accurate forestry measurements. Also try our board foot calculator and lumber calculator for complete construction planning.
Volume Calculator
Results
Select a calculation method and enter dimensions to see results
Wood Volume Calculation Methods
Rectangular Timber Volume
Volume = Length × Width × Height
Used for sawn lumber and rectangular timber pieces. Simply multiply the three dimensions to get cubic volume.
- Works with any rectangular lumber
- Supports multiple unit systems
- Accurate for construction lumber
- Easy to measure and calculate
Example Calculation:
Given: 2×4 lumber, 8 feet long
Actual dimensions: 1.5" × 3.5" × 8'
Calculation: 8 × (3.5/12) × (1.5/12) = 0.365 ft³
Result: 0.365 cubic feet per piece
Doyle Rule (Round Logs)
Volume = (D - 4)² × L ÷ 16
D = diameter (inches), L = length (feet)
Conservative scaling rule commonly used in eastern United States. Tends to underestimate volume for larger logs.
- Traditional scaling method
- Conservative estimates
- Good for smaller logs
- Widely accepted standard
Example Calculation:
Given: 12" diameter log, 16 feet long
Calculation: (12 - 4)² × 16 ÷ 16 = 64 board feet
Result: 64 BF ≈ 5.33 cubic feet
Note: Deducts 4" for bark and waste
International Rule (Round Logs)
Volume = 0.22 × D² × L - 0.71 × D × L
D = diameter (inches), L = length (feet)
More accurate for larger logs and commonly used in western regions. Provides better estimates for modern sawmill recovery.
- More accurate for large logs
- Modern scaling standard
- Better sawmill correlation
- Preferred for valuable timber
Example Calculation:
Given: 12" diameter log, 16 feet long
Calculation: 0.22 × 12² × 16 - 0.71 × 12 × 16
Step 1: 0.22 × 144 × 16 = 507.52
Step 2: 0.71 × 12 × 16 = 136.32
Result: 507.52 - 136.32 = 371.2 BF ≈ 30.9 ft³
Method Comparison Tool
Compare results from different calculation methods with the same log dimensions:
When to Use Each Method
Use Rectangular Volume When:
- Calculating sawn lumber volume
- Working with construction materials
- Measuring processed timber
- Planning storage space
- Converting between different units
Use Doyle Rule When:
- Working in eastern United States
- Dealing with smaller diameter logs
- Following traditional practices
- Conservative estimates needed
- Hardwood species evaluation
Use International Rule When:
- Working in western United States
- Measuring large diameter logs
- Modern sawmill operations
- Accurate volume estimates needed
- Softwood species evaluation
Step-by-Step Calculation Tutorial
How to Calculate Rectangular Timber Volume
1
Measure Length
Measure the length of your timber in feet. Use a tape measure for accuracy.
Tip: For multiple pieces of the same length, measure one
carefully and count the total pieces.
Length (feet)
2
Measure Width
Measure the width in inches. Remember to use actual dimensions, not nominal sizes.
Important: A "2×4" actually measures 1.5" × 3.5" after drying
and planing.
Common Nominal vs Actual Sizes:
| Nominal | Actual |
|---|---|
| 2×4 | 1.5" × 3.5" |
| 2×6 | 1.5" × 5.5" |
| 2×8 | 1.5" × 7.25" |
| 2×10 | 1.5" × 9.25" |
3
Measure Height/Thickness
Measure the height or thickness in inches, again using actual dimensions.
Tip: For boards lying flat, this is the thickness. For standing
lumber, this is the height.
4
Apply the Formula
Multiply: Length (ft) × Width (in) × Height (in), then convert to cubic feet.
Formula: Volume = L × W × H
Units: Length in feet, Width and Height in inches
Result: Volume in cubic feet
Try It Yourself:
How to Calculate Round Log Volume
1
Measure Diameter
Measure the diameter at the small end of the log in inches.
Tip: Use calipers or a diameter tape for accuracy. Measure
inside the bark.
Diameter Measurement Tips:
- Measure at the small end (top) of the log
- Measure inside the bark to the wood
- Take two measurements at right angles and average them
- Round down to the nearest inch for scaling
2
Measure Length
Measure the length of the log in feet.
Standard Lengths: Logs are typically cut in 2-foot increments
(8', 10', 12', 14', 16').
3
Choose Your Formula
Doyle Rule:
Volume = (D - 4)² × L ÷ 16
Best for: Smaller logs, conservative estimates
International Rule:
Volume = 0.22 × D² × L - 0.71 × D × L
Best for: Larger logs, accurate estimates
4
Calculate and Interpret
Interactive Log Calculator:
Understanding Unit Conversions
Length Conversions
| From | To | Multiply by | Example |
|---|---|---|---|
| Feet | Inches | 12 | 2 ft = 24 in |
| Inches | Feet | 1/12 (0.0833) | 24 in = 2 ft |
| Feet | Meters | 0.3048 | 10 ft = 3.048 m |
| Meters | Feet | 3.28084 | 3 m = 9.84 ft |
Volume Conversions
| From | To | Multiply by | Example |
|---|---|---|---|
| Cubic Feet | Cubic Meters | 0.0283168 | 10 ft³ = 0.283 m³ |
| Cubic Feet | Board Feet | ~12 | 1 ft³ ≈ 12 BF |
| Cubic Feet | Liters | 28.3168 | 1 ft³ = 28.32 L |
| Board Feet | Cubic Feet | 1/12 (0.0833) | 144 BF = 12 ft³ |
Practice Conversions
Convert: 5 cubic feet to cubic meters
Volume Unit Conversions
Common Volume Conversions
| From | To | Multiply by | Example |
|---|---|---|---|
| Cubic Feet | Cubic Meters | 0.0283168 | 10 ft³ = 0.283 m³ |
| Cubic Meters | Cubic Feet | 35.3147 | 1 m³ = 35.31 ft³ |
| Cubic Feet | Cubic Yards | 0.037037 | 27 ft³ = 1 yd³ |
| Cubic Feet | Board Feet | 12 (approx) | 1 ft³ ≈ 12 BF |
| Cubic Feet | Liters | 28.3168 | 1 ft³ = 28.32 L |
Conversion Notes
- Board Feet Conversion: The 1:12 ratio is approximate and varies based on lumber thickness and waste factors.
- Log Rules: Different scaling rules will give different results for the same log dimensions.
- Precision: Our calculator maintains 4 decimal places internally and rounds to 2 for display.
- Units: Always verify which units your supplier or customer expects.
Frequently Asked Questions
Doyle rule is more conservative and commonly used in the eastern US, while International rule is more accurate for larger logs and used in western regions. Doyle rule uses the formula (D-4)² × L / 16, while International rule uses 0.22 × D² × L - 0.71 × D × L. The International rule generally gives higher volume estimates, especially for larger diameter logs.
To convert cubic feet to cubic meters, multiply by 0.0283168. To convert cubic meters to cubic feet, multiply by 35.3147. Our calculator automatically shows results in both units for your convenience.
Most log scaling rules are designed for logs 6 inches or larger in diameter. Smaller logs may not follow standard scaling rules and should be measured individually. Our calculator will show a warning for logs under 6 inches in diameter.
For irregular shapes, you can use the rectangular timber calculator with average dimensions, or break the piece into multiple rectangular sections and calculate each separately. For very irregular pieces, consider measuring water displacement or using specialized forestry tools.
Our calculations use industry-standard formulas and are accurate for their intended purposes. However, actual lumber recovery can vary due to sawing methods, defects, and moisture content. These calculations should be used for estimation purposes, and professional verification is recommended for critical applications.