What is a Cord of Wood? Understanding Firewood Measurements
A cord of wood is the standard unit for measuring firewood volume in North America. By definition, a full cord measures exactly 4 feet high × 4 feet deep × 8 feet long, containing precisely 128 cubic feet of stacked wood and air space.
Understanding how to calculate a cord of wood is essential whether you’re buying firewood for your home, selling timber, or managing your woodlot. Our cord of word calculator takes the guesswork out of these measurements, helping you determine exactly how much wood you have and what it’s worth.
How to Calculate a Cord of Wood: Step-by-Step Guide
Basic Cord Calculation Formula
The fundamental cord of wood calculation follows this simple formula:
Volume (cubic feet) ÷ 128 = Number of Cords
Here’s how to measure and calculate your firewood stack:
Step 1: Measure Your Wood Stack
Measure three dimensions of your stacked firewood:
- Length: How far the stack extends horizontally
- Width (Depth): How deep the stack goes from front to back
- Height: How tall the stack reaches
Step 2: Calculate Cubic Feet
Multiply the three measurements together: Length × Width × Height = Total Cubic Feet
Step 3: Convert to Cords
Divide your total cubic feet by 128: Total Cubic Feet ÷ 128 = Cords of Wood
Real-World Firewood Calculation Examples
Example 1: Standard Backyard Stack
You have a firewood stack that measures:
- Length: 16 feet
- Width: 4 feet
- Height: 4 feet
Calculation: 16 ft × 4 ft × 4 ft = 256 cubic feet 256 ÷ 128 = 2.0 cords
Example 2: Compact Stack Against Garage
Your wood pile measures:
- Length: 12 feet
- Width: 2 feet
- Height: 6 feet
Calculation: 12 ft × 2 ft × 6 ft = 144 cubic feet
144 ÷ 128 = 1.125 cords
Example 3: Long, Low Stack
You’ve stacked wood in a long row:
- Length: 32 feet
- Width: 1.5 feet
- Height: 4 feet
Calculation: 32 ft × 1.5 ft × 4 ft = 192 cubic feet 192 ÷ 128 = 1.5 cords
Understanding Different Wood Measurements
Full Cord vs Face Cord vs Rick
- Full Cord: 4′ × 4′ × 8′ = 128 cubic feet
- Face Cord: 4′ × 8′ × 16″ = approximately 42.7 cubic feet (1/3 cord)
- Rick: Regional term, typically 4′ × 8′ × 2′ = 64 cubic feet (1/2 cord)
Stacking Factors: Why They Matter
Not all wood stacks are created equal. The stacking factor accounts for air gaps between logs:
- Loose stacking (70-75%): Irregular pieces, lots of air gaps
- Average stacking (80-85%): Typical homeowner organization
- Tight stacking (90-95%): Professional, uniform stacking
Our firewood volume calculator adjusts for these real-world stacking differences, giving you more accurate measurements than simple mathematical calculations.
Wood Moisture Content and Heat Output
How Moisture Affects Your Firewood Value
The moisture content of your wood significantly impacts its heating value:
- Kiln Dried (8–12% moisture): Super efficient. Burns hot and clean, great for wood stoves and indoor heating.
- Well Seasoned (15–20% moisture): This is your sweet spot. You’ll get strong heat with minimal smoke.
- Partially Seasoned (20–30% moisture): Burns okay, but you’ll notice lower heat and a bit more effort to keep the fire going.
- Semi-Green (30–40% moisture): Not ideal. A lot of energy is wasted just boiling off water.
- Green or Fresh Cut (40–60%+ moisture): Avoid if possible. It’s hard to light, smokes a lot, and delivers very little usable heat.
In our cord of wood calculator tool, you’ll see this reflected in your BTU output, moisture levels directly reduce the effective heat value.
🔥 Want to know how much wood your stove will actually burn this winter?
Try our Wood Heating Calculator to estimate your seasonal needs based on stove efficiency, home size, and local climate.
BTU Content by Wood Species
Different tree species provide varying amounts of heat per cord:
Top-Performing Hardwoods
- Osage Orange – 32.9M BTU/cord
- Shagbark Hickory – 27.7M BTU/cord
- Hornbeam (Ironwood) – 27.1M BTU/cord
- Black Locust / Black Birch – 26.8M BTU/cord
- Apple – ~26.5M BTU/cord
- White Oak – ~25.7M BTU/cord
Reliable Hardwoods
- Sugar Maple / Red Oak – 24.0M BTU/cord
- White Ash – 23.6M BTU/cord
- White Birch – ~20.2M BTU/cord
- Cherry – 20.0M BTU/cord
- Black Ash – ~19.5M BTU/cord
- Red Maple – 18.7M BTU/cord
Quick-Burning Woods
- Box Elder – 17.9M BTU/cord
- Alder – ~17.4M BTU/cord
- Aspen – 14.7M BTU/cord
- Basswood / Cottonwood – 13.5M BTU/cord
Softwoods for Kindling or Fast Heat
- Douglas Fir – ~18.1M BTU/cord
- White Pine – 14.3M BTU/cord
- Spruce – ~15.9M BTU/cord
- Cedar – 12.2M BTU/cord
Our cord of wood calculator calculates total usable heat output by combining wood species, moisture level, and even how tightly your stack is packed.
Using Our Advanced Cord of Wood Calculator
Key Features of Our Firewood Calculator
Our wood volume calculator offers several advantages over manual calculations:
- Multiple unit support: Calculate in feet or meters
- Stacking factor adjustment: Accounts for real stacking density
- Moisture content factors: Adjusts BTU calculations for wood condition
- International conversions: Shows results in cords, cubic meters, steres
- Cost calculations: Determines total price based on per-cord rates
When to Use a Cord of Wood Calculator
- Buying firewood: Verify you’re getting the amount you paid for
- Selling timber: Accurately price your wood inventory
- Insurance purposes: Document wood value for claims
- Heating planning: Calculate seasonal firewood needs
- Storage planning: Determine required storage space
Tips for Accurate Firewood Measurements
Best Practices for Measuring Wood Stacks
- Measure the outside dimensions of your stack
- Include air spaces in your measurements (they’re part of the cord definition)
- Use consistent units throughout your calculation
- Account for irregular stacking with appropriate stacking factors
- Measure multiple sections if your stack isn’t uniform
Common Measurement Mistakes to Avoid
- Measuring only the wood and ignoring air spaces
- Using different units without proper conversion
- Assuming all stacks have the same density
- Forgetting to account for wood species differences
- Not adjusting for moisture content
Regional Variations in Firewood Sales
Understanding Local Wood Markets
Firewood sales practices vary significantly by region:
United States:
- Standard measurement: Full cord (128 cu ft)
- Common sales unit: Face cord or full cord
- Typical prices: $150-400 per full cord
Canada:
- Metric measurements increasingly common
- Standard cord still widely used
- Price variations by province and species
Europe:
- Primary unit: Stere (1 cubic meter stacked)
- 1 stere ≈ 0.276 cords
- Sold by cubic meter or stere
Seasonal Firewood Planning
How Much Firewood Do You Need?
Average household firewood consumption varies by:
- Climate zone: Colder regions need 3-5+ cords annually
- Home size: Larger homes require proportionally more
- Heating efficiency: Modern stoves use less wood
- Supplemental heating: Primary vs. secondary heat source
Planning Your Firewood Purchase
For primary heating: 3-5 cords per heating season For supplemental heating: 1-2 cords per season
For occasional use: 0.5-1 cord per season
Frequently Asked Questions About Cord Calculations
How accurate are online cord of wood calculators?
Our cord of wood calculator provides professional-grade accuracy by accounting for stacking factors, moisture content, and species variations that simple volume calculations miss.
Can I measure firewood in metric units?
Yes! Our calculator supports both imperial (feet) and metric (meters) measurements, automatically converting between systems for accurate results.
What’s the difference between green and seasoned wood measurements?
While the physical volume remains the same, seasoned wood often stacks more tightly and provides significantly more heat output per cord due to lower moisture content.
How do I verify a firewood delivery?
Measure the delivered stack’s length, width, and height, then use our calculator to verify you received the correct amount. Account for stacking density in your calculations.
Conclusion: Master Your Firewood Calculations
Understanding how to properly calculate firewood volumes ensures you get fair value whether buying or selling wood. Our comprehensive cord of wood calculator eliminates guesswork by providing precise measurements that account for real-world factors like stacking density and wood moisture content.
Whether you’re a homeowner planning your winter heating needs, a landowner selling timber, or a firewood dealer pricing inventory, accurate cord calculations are essential for making informed decisions. Use our calculator along with these measurement techniques to confidently handle all your firewood volume needs.
Remember: a true cord contains 128 cubic feet of stacked wood and air space. With proper measurement techniques and our advanced calculator, you’ll never have to guess about your firewood quantities again.