Cord of Wood Calculator
An expert tool to accurately measure the volume of your stacked firewood.
Enter the total length of your wood pile.
Enter the width (or depth) of your wood pile. The unit is the same as selected above.
Enter the average height of your wood pile. The unit is the same as selected above.
Your stack is approximately:
1.00 Cords
What is a Cord of Wood?
A “cord of wood” is the official, legal unit of measurement for firewood in the United States and Canada. It is defined as a neatly stacked pile of wood occupying a volume of 128 cubic feet. To visualize this, imagine a stack of logs that is 4 feet high, 4 feet deep, and 8 feet long (4′ x 4′ x 8′). Any combination of dimensions that multiplies to 128 cubic feet is a cord.
This standardized measurement is crucial for consumers to ensure they are getting the amount of wood they pay for. Be wary of non-official terms like “face cord,” “rick,” “rack,” or “truckload,” as these can vary significantly in size and are often not legally defined. A face cord, for example, is typically the same height and length as a full cord (4′ x 8′) but only as deep as the length of a single log (commonly 16 inches), making it only one-third of a full cord.
The Formula to Calculate a Cord of Wood
Calculating the number of cords in your firewood stack is a straightforward volume calculation. The key is to ensure all your measurements are in the same unit (feet) before applying the final formula.
The formula is:
Cords = (Length in Feet × Width in Feet × Height in Feet) / 128
The number 128 is the constant, representing the total cubic feet in one standard cord. This calculator automatically handles conversions if you measure in inches.
| Variable | Meaning | Unit (Standard) | Typical Range |
|---|---|---|---|
| Length (L) | The longest horizontal dimension of the stack. | Feet (ft) | 2 ft – 50 ft |
| Width (W) | The depth of the stack (often the length of the logs). | Feet (ft) | 1.3 ft (16″) – 8 ft |
| Height (H) | The average vertical dimension of the stack. | Feet (ft) | 2 ft – 8 ft |
Practical Examples
Example 1: A Standard Full Cord
A firewood seller delivers a neatly stacked pile of wood advertised as a full cord. You measure it to confirm.
- Inputs: Length = 8 ft, Width = 4 ft, Height = 4 ft
- Calculation: (8 × 4 × 4) / 128 = 128 / 128
- Result: 1.0 Cord
Example 2: A Smaller, Non-Standard Stack
You have stacked wood from several trees you cleared. The pile is long but not very high or deep.
- Inputs: Length = 16 ft, Width = 2 ft (24 inches), Height = 3 ft
- Calculation: (16 × 2 × 3) / 128 = 96 / 128
- Result: 0.75 Cords
How to Use This Cord of Wood Calculator
Using this calculator is simple and ensures you get an accurate measurement of your firewood volume. Follow these steps:
- Select Your Unit: First, choose whether you will be entering your measurements in ‘feet’ or ‘inches’ from the dropdown menu next to the Length input. This selection will apply to all three dimension inputs.
- Measure Your Stack: Using a tape measure, find the three dimensions of your firewood pile. For non-uniform piles, try to measure the average dimension.
- Length: The longest side of the stack.
- Width: The depth of the stack.
- Height: The average height from the ground to the top of the pile.
- Enter the Dimensions: Type the numbers into the corresponding input fields (“Stack Length,” “Stack Width,” “Stack Height”).
- View the Results: The calculator will automatically update as you type. The primary result shows the total volume in cords. You can also see the total cubic feet and what percentage of a full cord your stack represents.
- Reset: Click the “Reset” button at any time to return the inputs to the standard dimensions of a full cord (8x4x4 feet).
Key Factors That Affect Firewood Measurement
The formula to calculate a cord of wood is precise, but the reality of stacking wood introduces variables. Achieving a true 128 cubic feet of solid wood is impossible due to air gaps. Here are key factors that influence the actual amount of wood you receive.
- Stacking Method: A tightly stacked pile with parallel logs will have far less air space than a loose, crisscrossed pile. The legal definition of a cord assumes wood is “racked and well stowed”.
- Log Shape and Size: Straight, uniform logs will pack together more efficiently than crooked, knotty, or round pieces. More air gaps mean less wood.
- Air Space: The space between logs is unavoidable. A standard cord may contain anywhere from 70 to 90 cubic feet of solid wood, with the rest being air.
- Settling: A freshly stacked pile of wood will settle over time, reducing its height and overall volume. It’s best to measure after the pile has had time to compact.
- Measurement on Uneven Ground: If your stack is on a slope, be sure to measure the height in several places and average the results for an accurate calculation.
- Log Length: While the standard formula works for any log length, sellers sometimes use terms like face cord, which is based on a specific log length (e.g., 16 inches). Always clarify what you are buying.
Frequently Asked Questions (FAQ)
1. How much is a cord of wood?
A cord is a measure of volume, not price. It is 128 cubic feet of stacked wood. The price of a cord varies dramatically based on location, wood type (hardwood vs. softwood), and whether it’s seasoned (dried) or green. You may also find our BTU comparison tool useful.
2. What’s the difference between a “full cord” and a “face cord”?
A full cord has a volume of 128 cubic feet (e.g., 4′ high x 8′ long x 4′ deep). A face cord typically has the same face dimensions (4′ x 8′) but is only as deep as the logs are cut, commonly 16 inches. Therefore, a face cord of 16″ logs is only 1/3 of a full cord.
3. How do I measure a pile that isn’t a perfect rectangle?
For irregularly shaped piles, take several measurements for height and length and use the average of each. For a round pile, you can approximate the volume, but it’s less accurate. Stacking it is the only way to be sure. Check out our guide on stacking firewood efficiently for tips.
4. Can I enter dimensions in inches in this calculator?
Yes. Use the dropdown menu next to the “Stack Length” input to select ‘inches’. The calculator will automatically convert all inputs to feet for the cord calculation.
5. Does the type of wood affect the volume of a cord?
No, a cord is strictly a measure of volume (128 cubic feet). However, the type of wood dramatically affects the weight and heat output. A cord of dense hardwood like oak will weigh much more and produce more heat than a cord of lightweight softwood like pine.
6. How much does a cord of wood weigh?
The weight varies significantly. A cord of green (freshly cut) hardwood can weigh over 4,500 pounds, while a cord of seasoned (dried) softwood might weigh 2,000-3,000 pounds.
7. How many pieces of wood are in a cord?
This is highly variable and depends on the size of the pieces. A cord could contain anywhere from 400 large pieces to over 1000 smaller, split pieces. It is not a reliable unit of measure.
8. How much is half a cord of wood?
Half a cord is 64 cubic feet. This could be a stack measuring 4 ft x 4 ft x 4 ft, for example.