Cord Firewood Calculator
Accurately determine the volume of your wood pile. Use this cord firewood calculator to calculate total cords, face cords, and heating potential in seconds.
1.00
Cords
128.0
1.0
24.0
Volume Comparison: Your Stack vs. Standard Cord (128 ft³)
What is a Cord Firewood Calculator?
A cord firewood calculator is an essential tool for homeowners, wood-burners, and timber sellers to measure the volume of fuel wood accurately. In North America, firewood is traditionally measured by the “cord.” However, because wood piles come in various shapes and sizes—and “face cords” are often confused with “full cords”—using a cord firewood calculator ensures you are getting exactly what you pay for.
A standard full cord is a large volume of wood, specifically 128 cubic feet. This cord firewood calculator takes the dimensions of your stack (length, height, and width) and converts them into this standard unit. Whether you are stocking up for winter or selling seasoned hardwood, knowing the precise volume helps in managing inventory and estimating heating capacity.
Common misconceptions include thinking any large pile is a cord or that a “truckload” automatically equals a cord. In reality, a standard pickup truck bed rarely holds more than half a cord, making the cord firewood calculator vital for verifying delivery amounts.
Cord Firewood Calculator Formula and Mathematical Explanation
The math behind our cord firewood calculator is based on three-dimensional geometry. The goal is to find the total volume in cubic feet and then normalize it to the standard cord unit.
The Core Formula:
Total Cords = (Length × Height × Width) / 128
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Length (L) | The total horizontal span of the stack | Feet | 4 ft – 24 ft |
| Height (H) | The vertical distance from ground to top | Feet | 2 ft – 6 ft |
| Width (W) | The depth of the pile (log length) | Feet | 1 ft – 4 ft |
| 128 | Cubic feet in a standard full cord | ft³ | Fixed Constant |
Face Cords vs. Full Cords
The cord firewood calculator also estimates “Face Cords.” A face cord is typically a stack 4 feet high and 8 feet long, but with a depth of only 16 inches (1.33 feet). This means a face cord is usually only one-third of a full cord, though this can vary depending on log length.
Practical Examples (Real-World Use Cases)
Example 1: The Standard Back-Yard Stack
Suppose you have a stack of wood that is 16 feet long, 4 feet high, and you cut your logs to 18 inches (1.5 feet).
Calculation: (16 × 4 × 1.5) = 96 cubic feet.
Using the cord firewood calculator: 96 / 128 = 0.75 Cords.
Financial Interpretation: If you paid for a full cord, you are 25% short.
Example 2: Commercial Delivery
A seller delivers two piles, each 8 feet long, 4 feet high, and 4 feet deep.
Calculation: 2 × (8 × 4 × 4) = 256 cubic feet.
Using the cord firewood calculator: 256 / 128 = 2.00 Cords.
Financial Interpretation: This is a perfect delivery of two full cords.
How to Use This Cord Firewood Calculator
- Measure the Length: Use a tape measure to find the total length of your wood pile in feet.
- Measure the Height: Measure from the bottom of the stack to the top. If the height is uneven, take measurements at several points and use the average.
- Measure the Width: This is the length of the logs themselves. Standard lengths are usually 16, 18, or 24 inches. Be sure to convert inches to feet (e.g., 16″ = 1.33 ft).
- Enter Data: Input these numbers into the cord firewood calculator above.
- Select Wood Type: Choose the species to get an estimate of the total heating energy (BTUs) available in your stack.
- Analyze Results: View the total cords and the visual comparison against a standard cord.
Key Factors That Affect Cord Firewood Calculator Results
- Stacking Tightness: The cord firewood calculator assumes wood is “well-stacked.” Loose piles with large air gaps will result in less actual wood than the volume suggests.
- Log Length (Width): Width is the most variable factor. A stack 4’x8′ with 12″ logs is only 1/4 of a cord, while the same stack with 48″ logs is a full cord.
- Species Density: While volume remains the same, the weight and energy content vary. Hardwoods provide more BTU per cord than softwoods.
- Moisture Content: Freshly cut “green” wood is much heavier and less efficient than seasoned wood. This tool calculates volume, not weight.
- Uneven Ground: If your pile is on a slope, ensure your height measurements are perpendicular to the length for accuracy in the cord firewood calculator.
- Bark Thickness: Thick bark (like on Cottonwood) takes up volume but provides less heat, which is why professionals often prefer clean-split logs.
Frequently Asked Questions (FAQ)
How many face cords are in a full cord?
Usually, there are 3 face cords in a full cord, assuming the logs are 16 inches long. If logs are 24 inches long, there are 2 face cords in a full cord.
Does the cord firewood calculator account for air space?
Yes, the standard 128 cubic feet measurement traditionally includes the wood, bark, and the air gaps between properly stacked logs.
What is a “thrown cord”?
A thrown cord is wood dropped into a truck or bin without stacking. It usually requires 180 cubic feet of space to equal 128 cubic feet of stacked wood.
Can I calculate volume for a circular stack (Holz Hausen)?
For circular stacks, the cord firewood calculator uses a different formula: π × radius² × height. You can approximate this by averaging the width and length.
Why does the BTU result change?
Different wood species have different densities. Oak has roughly 24-28 million BTUs per cord, while Pine may only have 14 million.
Is a truckload a cord?
Rarely. A standard 8-foot pickup bed filled to the rails is roughly 0.5 cords when stacked. If thrown in loose, it’s even less.
How accurate is this cord firewood calculator?
The math is 100% accurate; however, the result is only as good as your measurements and how tightly the wood is stacked.
Does wood shrink as it seasons?
Yes, as wood dries, it can shrink by 5-10% in volume. It’s best to use the cord firewood calculator on seasoned wood for the most “honest” measurement.
Related Tools and Internal Resources
- Firewood Seasoning Time Guide – Calculate how long your wood needs to dry based on species.
- Wood Species BTU Chart – A comprehensive list of heat values for different North American trees.
- Wood Storage Calculator – Determine how much shed space you need for your winter supply.
- Firewood Weight Calculator – Estimate the weight of your wood for transport safety.
- Stove Efficiency Guide – Learn how to maximize the BTUs calculated by our tool.
- Chimney Sweep Scheduler – Maintenance tips for heavy wood burners.