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Cord of Wood Calculator
Enter the length and height of your firewood stack and the length of the logs to see its volume in cubic feet and how many full or face cords it holds.
Your result
Sample values0.67
Full cords
85.3
Cubic feet stacked
2
Face cords
2,867
Pounds, seasoned oak
A 16 ft by 4 ft stack of 16 in logs.
For reference
| Measure | Value |
|---|---|
| Full cord | 128 ft³ — 4 × 4 × 8 ft |
| This stack | 85.3 ft³ |
| Face cord at 16 in | 42.7 ft³ |
| Seasoned oak, per cord | about 4,300 lb |
Cord of Wood Calculator: Estimate Your Firewood Volume
A cord of wood calculator helps you determine how much firewood you have by measuring the length, height, and depth of a stacked pile. Whether you are buying firewood for winter, selling seasoned logs, or estimating how much wood you have stored, calculating the stack volume makes it easier to compare quantities and plan your supply.
The calculator uses stack dimensions, log length, measurement units, wood species, and wood condition to estimate firewood volume and the equivalent number of cords. Understanding these measurements helps you avoid paying for less firewood than expected and makes it easier to compare different deliveries.
What Is a Cord of Wood?
A cord is a standard unit of measurement for firewood in the United States. One full cord represents a stacked volume of 128 cubic feet, including the spaces between the individual logs.
A typical full cord is arranged in a stack measuring:
- 8 feet long
- 4 feet high
- 4 feet deep
The depth usually corresponds to the length of the firewood pieces. If the logs are 16 inches long, a full cord requires enough pieces arranged in rows to create a stack with a total depth of 4 feet.
The actual shape of a stack can vary, but its total stacked volume determines the cord measurement.
A cord of wood calculator is useful for:
- Estimating the quantity of firewood in an existing stack
- Checking the quantity delivered by a firewood supplier
- Calculating cords for different log lengths
- Comparing firewood prices by cord or fraction of a cord
- Planning storage space for seasonal firewood
- Estimating the volume of seasoned or green firewood
A cord measures the overall stacked volume, not the solid volume of the wood alone. The gaps between logs are included in the measurement.
How Does a Cord of Wood Calculator Work?
The calculator uses three main dimensions: stack length, stack height, and log length. These measurements establish the approximate volume occupied by the stacked firewood.
1. Measure the Stack Length
Stack length is the horizontal distance from one end of the pile to the other. Measure along the front of the stack, keeping the tape measure parallel to the ground.
For example, a pile that extends 8 feet from end to end has a stack length of 8 feet.
2. Measure the Stack Height
Stack height is the vertical distance from the bottom of the pile to its highest point. For a neatly arranged stack, measure from the supporting surface to the top of the logs.
If the stack is uneven, take several height measurements and use a reasonable average. A single measurement at the tallest point may overestimate the volume of an irregular pile.
3. Measure the Log Length
Log length determines the depth of the stack when the pieces are arranged in parallel rows.
Common firewood lengths include 12, 16, and 18 inches, although actual dimensions vary by supplier and intended use. Measure the pieces rather than assuming every log has the advertised length.
Convert inches into feet before calculating volume:
16 inches ÷ 12 = 1.333 feet
If the stack is 8 feet long and 4 feet high, with logs 16 inches long, the estimated volume is:
8 × 4 × 1.333 = 42.67 cubic feet
This is approximately one-third of a full cord.
Cord of Wood Calculation Formula
The standard formula for estimating stacked firewood volume is:
V = L × H × D
- V = stacked volume in cubic feet
- L = stack length in feet
- H = stack height in feet
- D = log length, expressed as stack depth in feet
All dimensions must use compatible units. If the log length is measured in inches, divide it by 12 before multiplying.
Convert Cubic Feet Into Cords
Once you calculate the stack volume, divide the result by 128:
Cords = V ÷ 128
For example, a stack containing 64 cubic feet occupies:
64 ÷ 128 = 0.5 cord
This means the stack contains half a cord based on its measured dimensions.
Calculate the Required Stack Dimensions
You can also rearrange the formula to estimate the stack length needed for a particular quantity of firewood.
L = V ÷ (H × D)
Suppose you want to stack half a cord using 16-inch logs and a stack height of 4 feet. Half a cord occupies 64 cubic feet, so the required stack length is approximately:
64 ÷ (4 × 1.333) ≈ 12 feet
This calculation helps you plan a firewood storage area before delivery.
Inputs Required by the Cord of Wood Calculator
Enter the following information to estimate the amount of firewood in your stack.
| Input | Description | Purpose |
|---|---|---|
| Stack length | Horizontal length of the pile | Determines the stack’s overall size |
| Stack height | Vertical height of the pile | Establishes the stack’s height |
| Log length | Length of each firewood piece | Determines the stack depth |
| Measurement units | Feet, inches, or other supported units | Ensures consistent calculations |
| Wood species | Oak, maple, birch, or pine | Identifies the type of firewood |
| Wood condition | Seasoned or green | Identifies the moisture condition of the wood |
The stack dimensions and log length determine the calculated volume. Wood species and condition provide additional material context, but they do not change the geometric cord calculation when the dimensions remain the same.
For instance, a properly measured stack of oak and a stack of pine with identical dimensions have the same stacked volume. Their weight, energy content, and burning characteristics may differ considerably.
Practical Cord of Wood Calculation Example
Consider a homeowner who has purchased a stack of firewood for winter heating. The pile measures 12 feet long and 4 feet high, and each log is 16 inches long.
Convert log length
16 ÷ 12 = 1.333 feet
Calculate stack volume
12 × 4 × 1.333 = 63.98 cubic feet
Calculate cords
63.98 ÷ 128 ≈ 0.50 cord
The measured stack contains approximately half a cord of firewood.
| Measurement | Result |
|---|---|
| Stack length | 12 feet |
| Stack height | 4 feet |
| Log length | 16 inches |
| Calculated volume | 63.98 cubic feet |
| Equivalent quantity | Approximately 0.50 cord |
This example assumes the logs are stacked in an orderly arrangement and that the stated dimensions represent the full pile. If the stack is uneven or contains substantial gaps beyond those normally found in stacked firewood, the estimate may be less representative.
Full Cord vs. Face Cord vs. Fractional Cord
Understanding firewood terminology helps you compare quantities when purchasing wood.
| Measurement | Typical dimensions | Stacked volume |
|---|---|---|
| Full cord | 8 ft × 4 ft × 4 ft | 128 cu ft |
| Half cord | Equivalent stacked volume | 64 cu ft |
| Quarter cord | Equivalent stacked volume | 32 cu ft |
| Face cord with 16-inch logs | 8 ft × 4 ft × 16 in | Approximately 42.67 cu ft |
A face cord is commonly used to describe a stack measuring 8 feet long and 4 feet high, with depth determined by log length. Its volume is not fixed unless the log length is specified.
For 16-inch logs, a face cord represents approximately one-third of a full cord. A face cord made with 24-inch logs contains a different stacked volume.
Because firewood terminology can vary by seller and location, confirm the actual dimensions and quantity before purchasing.
How Wood Species and Condition Affect Firewood
The calculator includes wood species and condition because these characteristics matter when choosing and storing firewood. However, their influence is different from that of stack dimensions.
Wood Species
Different species have different densities and energy content. Oak and maple are generally denser hardwoods, while pine is a less dense softwood. Birch has its own density and burning characteristics.
For a similar quantity of properly seasoned wood, denser species generally provide more energy per unit of volume than less dense species. Actual performance depends on the specific species, moisture content, and combustion conditions.
Selecting the species helps you evaluate the firewood’s likely heating characteristics, but species alone cannot determine the exact weight or heat output of a stack.
Seasoned vs. Green Firewood
Green firewood contains more moisture than properly seasoned firewood. This additional moisture affects weight, ignition, combustion efficiency, and the amount of useful heat released.
Seasoned wood has had time to dry, although the time required depends on the species, log size, climate, airflow, and storage conditions. Moisture content should be measured rather than assumed from appearance alone.
Green and seasoned firewood stacks with identical external dimensions occupy the same calculated stacked volume. Their weights may differ substantially because of their moisture content.
Factors That Affect Calculation Accuracy
Several practical factors can influence the reliability of a cord estimate.
- Irregular stacking: Uneven piles make it harder to identify representative length and height measurements.
- Inconsistent log lengths: Pieces of different lengths can create an uneven stack depth.
- Incorrect unit conversion: Mixing inches and feet without conversion produces incorrect volumes.
- Loose stacking: Poorly arranged logs can create larger gaps and make comparisons with neatly stacked firewood less reliable.
- Ground slope: A sloping storage surface can make stack height difficult to measure consistently.
- Rounded dimensions: Estimating measurements rather than using a tape measure introduces avoidable errors.
For the most useful result, arrange firewood neatly, measure the stack at several points if necessary, and use consistent units. Treat the output as an estimate when the pile is irregular or loosely arranged.
Common Mistakes When Calculating Cords of Wood
Avoid these errors when calculating firewood volume:
- Confusing a face cord with a full cord: A face cord’s volume depends on the log length.
- Ignoring log length: Stack length and height alone are insufficient to calculate three-dimensional volume.
- Counting air gaps as solid wood: A cord includes the spaces between stacked logs.
- Assuming all species weigh the same: Wood density varies by species and moisture content.
- Treating green and seasoned wood as identical in weight: Their moisture levels can differ substantially.
- Relying only on a seller’s label: Verify the actual stack dimensions and agreed quantity.
Benefits of Using a Cord of Wood Calculator
A cord of wood calculator makes firewood measurement easier for homeowners, sellers, and property managers.
- Quick volume estimates: Calculate stacked cubic feet and equivalent cords in seconds.
- Better purchase comparisons: Compare measured quantities with advertised cord sizes.
- Storage planning: Estimate how much space is needed for a seasonal wood supply.
- Consistent measurements: Use the same formula for different stack dimensions and log lengths.
- Improved inventory management: Estimate the firewood remaining in a storage pile.
By combining accurate measurements with an understanding of cord terminology, you can make more informed decisions when buying, selling, or storing firewood.
Questions
Frequently Asked Questions
One full cord contains 128 cubic feet of stacked firewood, including the spaces between logs. A typical stack measures 8 feet long, 4 feet high, and 4 feet deep.
Multiply the stack length, height, and log length in feet to calculate stacked volume. Divide the result by 128 to estimate the number of cords.
The quantity depends on the log length. A stack measuring 8 feet long, 4 feet high, and 16 inches deep contains approximately 42.67 cubic feet, or one-third of a cord.
No. The cord measurement depends on stacked dimensions, not species. However, oak, maple, birch, and pine can differ in density, weight, moisture, and heating performance.
A typical full cord occupies 128 cubic feet of stacked space. Allow additional room for access, airflow, and safe handling when planning your storage area.
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