Cord of Wood Calculator
Accurately measure your firewood pile in cords and cubic feet.
Calculate Your Firewood Volume
Visualizing Your Woodpile vs. a Full Cord
Common Firewood Measurements
| Unit | Dimensions (H x W x L) | Cubic Feet (ft³) | Notes |
|---|---|---|---|
| Full Cord | 4 ft x 4 ft x 8 ft | 128 | The legal, standard unit for selling firewood in most regions. |
| Face Cord (Rick) | 4 ft x 1.33 ft (16″) x 8 ft | ~42.6 | One-third of a full cord, based on 16-inch log lengths. |
| Half Cord | 4 ft x 4 ft x 4 ft | 64 | Exactly half the volume of a full cord. |
| Short Bed Pickup | ~2 ft x 5.5 ft x 5.5 ft | ~60 (loosely thrown) | Highly variable; stacking adds ~20-30% more wood than throwing. |
| Long Bed Pickup | ~2 ft x 5.5 ft x 8 ft | ~88 (loosely thrown) | Can hold over a half-cord if tightly stacked to the rails. |
A) What is a Cord of Wood?
A “cord” is the official unit of measurement for firewood in the United States and Canada. When you accurately calculate cord of wood volume, you are measuring a specific quantity of neatly stacked logs. Legally, a full cord is defined as a stack of wood that occupies a volume of 128 cubic feet. This standard measurement ensures that both buyers and sellers have a consistent and fair way to trade firewood. The most common configuration for a cord is a stack that is 4 feet high, 4 feet deep, and 8 feet long (4 x 4 x 8 = 128). However, any stack dimensions that multiply to 128 cubic feet are technically a cord.
Anyone who buys or sells firewood should use this measurement. For homeowners, understanding how to calculate cord of wood ensures you receive the amount you paid for. For sellers, it’s a legal and professional standard. A common misconception is that a “face cord,” “rick,” or “truckload” is equivalent to a full cord. These terms are often smaller, non-standard units and can be misleading if you don’t verify the cubic footage. This calculator helps you confirm the precise volume.
B) Cord of Wood Formula and Mathematical Explanation
The formula to calculate cord of wood is straightforward and based on the geometric principle of a rectangular prism’s volume: Volume = Length × Width × Height. Since a standard cord is 128 cubic feet, we use this value as our denominator to convert the stack’s volume into cords.
The Formula:
Number of Cords = (Stack Length (ft) × Stack Height (ft) × Stack Width (ft)) / 128
The process involves three simple steps:
- Measure the three dimensions of your neatly stacked woodpile in feet.
- Multiply these three measurements together to get the total volume in cubic feet.
- Divide the total cubic feet by 128 to determine the number of cords.
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Length (L) | The longest horizontal dimension of the woodpile. | Feet (ft) | 5 – 50 ft |
| Height (H) | The vertical dimension from the ground to the top of the stack. | Feet (ft) | 2 – 6 ft |
| Width (W) | The depth of the stack, typically the length of the individual logs. | Feet (ft) | 1.33 ft (16″) – 4 ft |
| Volume | The total space occupied by the wood and air gaps. | Cubic Feet (ft³) | 40 – 500 ft³ |
C) Practical Examples (Real-World Use Cases)
Example 1: Standard Homeowner’s Woodpile
A homeowner buys firewood and stacks it against their garage wall. The pile is 12 feet long and is stacked to an average height of 4 feet. The logs were cut to a standard 16 inches (which is 1.33 feet).
- Inputs: Length = 12 ft, Height = 4 ft, Width = 1.33 ft
- Calculation: (12 × 4 × 1.33) = 63.84 cubic feet
- Cord Calculation: 63.84 / 128 = 0.498 Cords
- Interpretation: The homeowner has almost exactly a half-cord of wood. If they paid for a full cord, they are missing about half of their order. This shows the importance of the need to calculate cord of wood yourself.
Example 2: Large Bulk Delivery
Someone with a large wood stove receives a bulk delivery. They create two stacks. The first is 8 ft long, 4 ft high, and 4 ft deep. The second, smaller stack is 6 ft long, 4 ft high, and 2 ft deep (made of shorter pieces).
- Stack 1 Calculation: (8 × 4 × 4) = 128 cubic feet (1 full cord)
- Stack 2 Calculation: (6 × 4 × 2) = 48 cubic feet (48 / 128 = 0.375 cords)
- Total Cords: 1.0 + 0.375 = 1.375 Cords
- Interpretation: The total delivery was one and three-eighths of a cord. Using a reliable method to calculate cord of wood is essential for verifying bulk purchases. For more information on wood heating values, see our BTU Comparison Chart.
D) How to Use This Calculate Cord of Wood Calculator
Our calculator simplifies the process of determining your firewood volume. Follow these steps for an accurate measurement:
- Measure Your Pile: Use a tape measure to find the length, height, and width of your woodpile in feet. For uneven piles, take several measurements and use the average.
- Enter the Dimensions: Input your average length, height, and width into the designated fields. The width is simply the average length of your logs.
- Read the Results: The calculator instantly updates to show your total volume in cords (the primary result), as well as the total cubic feet, approximate face cords, and the percentage of a full cord you have.
- Make Decisions: Use these results to verify purchases, estimate how long your wood supply will last, or plan future firewood needs. The ability to quickly calculate cord of wood empowers you in any transaction.
E) Key Factors That Affect Cord of Wood Results
The mathematical volume is just one part of the story. Several factors influence the actual amount of usable wood fiber you receive in a cord.
- Stacking Tightness: The 128 cubic foot measurement assumes the wood is “racked and well stowed,” meaning it’s stacked neatly with minimal gaps. Loosely thrown piles can have 30-40% less wood than a compact stack of the same volume.
- Log Diameter: Piles of large, round logs will have more air space than piles of smaller, split pieces. You get more solid wood fiber when the pieces fit together tightly.
- Crooked vs. Straight Wood: Crooked or knotty logs create large, irregular gaps, significantly reducing the amount of wood in the stack. A proper cord of wood calculation should ideally be done with straight, consistently sized pieces.
- Log Length Consistency: If log lengths vary, the stack’s width will be inconsistent, making an accurate volume calculation more challenging. Measure the average width for the best estimate.
- Bark Thickness: Some wood species have very thick bark, which contributes to the volume but not the burnable wood fiber. This is a minor factor but can make a difference.
- Settling: A freshly stacked pile will settle over time as the pieces shift and moisture evaporates, slightly reducing its height and overall volume. Our guide on Safe Firewood Stacking can help minimize this.
F) Frequently Asked Questions (FAQ)
A full cord is a legal unit measuring 128 cubic feet. A face cord is a stack 4 ft high and 8 ft long, but only as deep as the logs are cut—usually 16 inches (1.33 ft). A 16-inch face cord is therefore one-third of a full cord. Always clarify which “cord” is being sold. This is why you must calculate cord of wood volume to be sure.
Weight varies dramatically by wood species and moisture content. A cord of green (wet) oak can weigh over 5,000 lbs, while a cord of dry pine might weigh under 2,500 lbs. Volume, not weight, is the standard for measurement.
You can’t accurately measure a loose pile. The only way to verify the volume is to stack it neatly and then use this calculator. A loose pile’s volume is deceptive due to the large amount of air space. For tips, read about proper wood stacking techniques.
This is a common issue. It could be due to a misunderstanding of terms (e.g., they sold a face cord but called it a cord), loose stacking, or an honest mistake. Use your calculation as a basis for a polite conversation with the seller.
This depends on your climate, home insulation, stove efficiency, and how often you burn. For someone heating exclusively with wood in a cold climate, a cord might last 4-8 weeks. For occasional fires, it could last an entire winter. A correct calculate cord of wood is the first step in estimating your supply.
Seasoned (dry) wood is far superior. It ignites easier, produces more heat, and creates less creosote buildup in your chimney. Green wood is cheaper but must be stacked and dried for 6-18 months before use. Learn more in our Wood Seasoning Guide.
A half-cord is 64 cubic feet. A common stack size is 4 ft high, 4 ft deep, and 4 ft long (4x4x4=64). Another way to calculate cord of wood for a half-cord is 8 ft long by 4 ft high by 2 ft deep.
No, a cord is strictly a measure of volume (128 cubic feet). However, the type of wood (e.g., dense hardwood like oak vs. light softwood like pine) will greatly affect the total weight and the amount of heat energy stored in that volume. Always check a Firewood BTU Ratings chart.
G) Related Tools and Internal Resources
Continue your research with our other specialized tools and guides:
- BTU Comparison Chart: Compare the heat output of different wood species to choose the most efficient firewood for your needs.
- Guide to Seasoning Firewood: Learn the best practices for drying your wood to maximize heat and minimize smoke.
- Safe Firewood Stacking Guide: Explore techniques for building stable, well-aerated woodpiles that promote drying and prevent collapse.
- Chainsaw Fuel Mix Calculator: If you cut your own wood, use this tool to get the perfect oil and gas mixture every time.