Wood Cord Calculator
Accurately measure your firewood stack in seconds.
*Assuming 16-inch log lengths for face cord calculation.
What is a Wood Cord?
A “cord” is the official unit of measurement for firewood in the United States and Canada. When you buy or sell firewood, this is the standard volume you should refer to. A full cord is a neatly stacked pile of wood measuring 128 cubic feet. The most common dimensions for a full cord are 4 feet high, 4 feet wide (deep), and 8 feet long (4′ x 4′ x 8′). Using a reliable wood cord calculator ensures you are getting the volume you paid for.
This measurement is crucial for anyone who uses a wood-burning stove or fireplace. It helps in planning how much wood to purchase for the winter and provides a standard for fair transactions. A common misconception involves the “face cord” or “rick,” which is much smaller than a full cord. A face cord has the same height and length (4′ x 8′) but is only as deep as the length of a single log, typically 16 inches. This makes a 16-inch face cord only one-third of a full cord. Our wood cord calculator helps clarify these differences.
Wood Cord Formula and Mathematical Explanation
The calculation for determining the number of cords in a stack of wood is straightforward. The core of the calculation is to find the total volume of the stack in cubic feet and then divide it by the volume of a standard cord, which is 128 cubic feet.
The formula is:
Total Cords = (Stack Length [ft] × Stack Height [ft] × Stack Width [ft]) / 128
Using a wood cord calculator automates this process, but understanding the math is simple. For example, if you have a stack that is 8 feet long, 4 feet high, and 4 feet wide, the calculation is (8 × 4 × 4) / 128 = 1 cord.
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Stack Length | The horizontal length of the wood pile. | Feet (ft) | 2 – 50 ft |
| Stack Height | The vertical height of the wood pile. | Feet (ft) | 2 – 8 ft |
| Stack Width (Depth) | The depth of the wood pile, often equal to the log length. | Feet (ft) | 1.33 (16 in) – 4 ft |
| Total Volume | The total cubic space occupied by the stack. | Cubic Feet (ft³) | 10 – 2000+ ft³ |
| Cords | The final calculated volume in standard cords. | Cords | 0.1 – 15+ |
Practical Examples (Real-World Use Cases)
Understanding how to apply the wood cord calculator in real scenarios is key. Here are a couple of examples:
Example 1: Verifying a “Full Cord” Delivery
You order a “full cord” of firewood. After stacking it, your pile measures 9 feet long, 4 feet high, and the logs are cut to an average depth of 3.5 feet.
- Inputs: Length = 9 ft, Height = 4 ft, Width = 3.5 ft
- Calculation: (9 × 4 × 3.5) = 126 cubic feet.
- Result: 126 / 128 = 0.98 cords.
Interpretation: The delivery was slightly short of a full cord. While close, this demonstrates the importance of measuring instead of assuming.
Example 2: Calculating a Large, Irregular Pile
You have a long stack of wood along a fence line. It measures 20 feet long and is stacked 5 feet high. The logs are all 16 inches long (which is 1.33 feet).
- Inputs: Length = 20 ft, Height = 5 ft, Width = 1.33 ft
- Calculation: (20 × 5 × 1.33) = 133 cubic feet.
- Result: 133 / 128 = 1.04 cords.
Interpretation: Even though the pile is long and narrow, it contains just over a full cord of wood. This is a common scenario for those using a firewood calculator to measure wood stacked for personal use.
How to Use This Wood Cord Calculator
Our wood cord calculator is designed for simplicity and accuracy. Follow these steps to get your measurement:
- Measure Your Stack: Use a tape measure to find the average length, height, and width (depth) of your firewood pile in feet. For irregular piles, it’s best to take measurements at several points and average them.
- Enter the Dimensions: Input your averaged measurements into the corresponding fields: “Stack Length (feet)”, “Stack Height (feet)”, and “Stack Width (feet)”.
- Read the Results: The calculator will instantly update. The primary result shows the total number of cords. You can also see the total volume in cubic feet and the equivalent number of face cords.
- Analyze the Chart: The bar chart provides a quick visual comparison of your stack’s total volume against the standard 128 cubic feet of a full cord.
Key Factors That Affect Wood Volume Results
The result from a wood cord calculator is based on the outer dimensions of the stack, but the actual amount of solid wood can vary. Several factors influence this:
- Stacking Method: Tightly stacked wood with minimal gaps will contain more solid wood per cord than a loosely stacked pile. Criss-crossing logs leaves more air space.
- Log Shape and Size: Straight, uniform logs will pack together more densely. Crooked, knotty, or round (unsplit) logs create larger air gaps, reducing the actual wood volume.
- Log Length Consistency: If log lengths vary, the stack’s width may be inconsistent, making an accurate average measurement more difficult.
- Air Space: A standard cord measurement assumes a certain percentage of the volume is air. This can range from 20% to 40% depending on the factors above. Our wood cord calculator gives the gross volume, which is the industry standard.
- Settling: A freshly stacked pile will settle over time as the wood dries and shifts, potentially reducing its height and overall measured volume.
- Bark Thickness: The type of tree affects bark thickness, which contributes to the overall volume but not the burnable wood fiber.
For more on wood types, see our BTU of Different Woods guide.
Frequently Asked Questions (FAQ)
A full cord is a volume of 128 cubic feet (e.g., 4’x4’x8′). A face cord is a stack 4′ high by 8′ long, but its depth is only the length of one piece of firewood (usually 16 or 24 inches). A 16″ face cord is 1/3 of a full cord.
The weight varies significantly based on wood density (species) and moisture content. A cord of green (wet) oak can weigh over 5,000 lbs, while a seasoned cord of pine might weigh 2,500 lbs. To learn more, check out our guide on seasoning firewood.
Always stack and measure the wood yourself. Use a reliable wood cord calculator like this one. A legitimate seller should be transparent about their measurements and guarantee the volume.
No, a wood cord calculator requires a stacked pile for accurate measurement. A loose pile has far too much air space to estimate volume reliably. Wood must be stacked to be measured in cords.
Many commercially sold “full cord” racks have dimensions that only hold about 2/3 of a true cord. Always check the rack’s actual dimensions (L x H x W) and calculate its cubic volume.
Yes. Burning unseasoned (green) wood produces more smoke and creosote, a flammable tar-like substance that can build up in your chimney and cause a dangerous chimney fire.
It depends on the log length. If the logs are 16 inches long, there are three face cords in a full cord (16″ x 3 = 48″ or 4 feet). If logs are 12 inches long, there would be four face cords. Our wood cord calculator helps visualize this.
Buying by the cord (volume) is the standard and generally fairer, as weight is heavily influenced by water content. You could end up paying for water instead of wood if you buy by weight.