How To Calculate A Cord Of Firewood

How to Calculate a Cord of Firewood: A Comprehensive Guide

Buying firewood can be a significant expense, especially if you're heating your home with it. Understanding how to calculate a cord of firewood is crucial to ensuring you're getting a fair price and the right amount of wood for your needs. This comprehensive guide will walk you through various methods, addressing common misconceptions and helping you confidently navigate the world of firewood purchasing.

What is a Cord of Firewood?

A cord of firewood is a standard unit of measurement, representing a stack of wood measuring 4 feet wide, 4 feet high, and 8 feet long. This results in a total volume of 128 cubic feet. However, the actual amount of usable wood can vary significantly depending on several factors we'll discuss later.

Understanding the Variations: Face Cord, Rick, and Other Measurements

While the cord is the standard, other measurements are frequently used, leading to potential confusion and price discrepancies. It's vital to understand these differences to avoid being overcharged.

Face Cord

A face cord is a stack of wood that's 4 feet high and 8 feet long, but the depth (thickness) is variable. This is often a shorter length, typically 16 inches (1.33 feet). This means a face cord contains only approximately 42.67 cubic feet of wood, significantly less than a full cord. Always clarify the depth when purchasing a face cord.

Rick

The term "rick" is less standardized than a cord or face cord, representing a loosely piled stack of firewood. It's virtually impossible to accurately calculate the volume of a rick, making it a risky purchase unless you're extremely familiar with the seller and their stacking practices. Avoid buying firewood by the "rick" if you want accurate volume.

Other Units

Some sellers might use other units like cubic feet or even truckloads. These are even less standardized than a rick and require careful negotiation and verification. Always insist on clear measurement specifications to protect yourself.

Calculating a Cord: Different Methods

There are several ways to estimate or precisely calculate a cord of firewood, depending on the shape and arrangement of the wood.

Method 1: The Standard Cord Calculation

This is the simplest method, applicable when the wood is neatly stacked in a 4ft x 4ft x 8ft rectangle.

• Dimensions: Measure the length, width, and height of the stack in feet.
• Calculation: Multiply the three dimensions (length x width x height). If your stack is a true cord, this will equal 128 cubic feet (4ft x 4ft x 8ft = 128 cubic feet).

Method 2: Calculating Irregular Stacks

Many wood stacks aren't perfectly rectangular. For irregular stacks, you'll need to break down the calculation into smaller, more manageable sections.

• Sectioning: Divide the stack into smaller, more regular-shaped sections (cubes, rectangular prisms, etc.).
• Individual Volume: Calculate the volume of each section separately using the formula (length x width x height).
• Total Volume: Add the volumes of all sections together to get the total volume in cubic feet.
• Cord Conversion: Divide the total volume by 128 to determine the number of cords.

Method 3: Estimating with Visual Inspection

This is less precise but can be helpful for quick estimations. Familiarity with the size of a standard cord is essential for this method.

• Visual Comparison: Compare the stack to your mental image or a photograph of a known cord.
• Adjustment: Adjust your estimate based on any noticeable differences in height, width, or length. This method is highly subjective and prone to significant error.

Factors Affecting the Usable Wood Volume

Even if you've accurately measured a cord, the actual amount of usable wood can vary. Consider these factors:

Wood Species

Different wood species have varying densities. Dense hardwoods like oak will yield more BTU (British Thermal Units) per cord than lighter softwoods like pine. A cord of oak will burn longer and provide more heat.

Splitting and Size of Wood

Smaller pieces of wood generally burn more efficiently than larger logs. Proper splitting maximizes the surface area exposed to oxygen, leading to better combustion. Larger pieces can contain more air space within the stack, leading to a less dense cord.

Wood Moisture Content

"Seasoned" wood, with a moisture content of 20% or less, burns more efficiently and produces more heat. Green (unseasoned) wood contains significantly more water, which reduces its heating value and can lead to creosote buildup in your chimney. A cord of green wood will have a smaller amount of actual burnable wood.

Stacking Technique

Loosely stacked wood will contain significantly more air gaps, reducing the actual wood volume and overall heating value. A tightly stacked cord will have a much higher energy density compared to a loose stack.

Avoiding Common Mistakes When Buying Firewood

• Unclear Measurements: Always clarify the measurement method used (cord, face cord, rick, etc.) and the dimensions of the stack before purchasing.
• Poor Stacking: Inspect the stack for loose stacking or excessive air gaps. A tightly stacked cord is essential.
• Unseasoned Wood: Check the moisture content of the wood; seasoned wood is crucial for efficient burning and maximum heat output.
• Hidden Costs: Ensure the price includes delivery if applicable. Inquire about any additional fees or charges.
• Type of Wood: Choose the appropriate wood type based on your needs and budget.

Calculating the Cost Per Cord

Once you've determined the volume of firewood in cords, you can easily calculate the cost per cord.

• Total Cost: Obtain the total cost of the firewood purchase.
• Total Cordage: Determine the total number of cords purchased.
• Cost per Cord: Divide the total cost by the total cordage. This calculation gives you the cost per cord, allowing you to compare prices from different suppliers.

Conclusion

Accurately calculating a cord of firewood is essential for ensuring a fair price and receiving the expected amount of wood. Understanding the different measurement units, factoring in variations in stacking and wood density, and being aware of potential pitfalls will save you money and frustration. By employing the methods outlined above and being a diligent buyer, you can confidently purchase the right amount of firewood to keep you warm throughout the colder months. Remember to always clarify the measurement method and inspect the stack carefully before finalizing your purchase.