Measuring a trailer accurately is crucial for various reasons, from ensuring safe towing and compliance with regulations to determining storage space and assessing compatibility with your towing vehicle. Understanding how to measure a trailer involves more than just grabbing a tape measure; it requires knowledge of key measurement points and the specific terminology used in the trailer industry.
Understanding Trailer Measurement Fundamentals
Accurate trailer measurements are essential for legal compliance, safe towing, and efficient space management. Overall length, width, and height are the core dimensions you’ll need, along with key features like deck length, tongue length, and interior dimensions depending on your needs. Let’s delve into each of these critical aspects.
Overall Trailer Length
Overall trailer length is the total distance from the tip of the tongue (or coupler) to the very back of the trailer, including any protruding hardware like lights or bumpers. This is a critical measurement for storage planning and ensuring compliance with state regulations regarding trailer length limits. It’s the most common measurement asked for by authorities.
Overall Trailer Width
Overall trailer width measures the widest point of the trailer, typically from the outside edge of one fender to the outside edge of the opposite fender. For trailers without fenders, the width is measured from the outside edge of the trailer body to the outside edge of the opposite side. This measurement is crucial for road safety and ensuring you can navigate narrow roads or driveways.
Overall Trailer Height
Overall trailer height is measured from the ground to the highest point of the trailer. This usually includes the top of the roof (for enclosed trailers) or the top of any installed equipment like racks or cargo carriers. Knowing the height is essential for avoiding collisions with bridges, overpasses, and other overhead obstructions.
Deck Length and Width
Deck length (or bed length) refers to the usable cargo space on a flatbed or open trailer. This is the length of the trailer platform itself. Similarly, deck width is the usable width of the trailer platform. These measurements are paramount for determining whether the trailer can accommodate specific cargo dimensions.
Tongue Length
Tongue length, also known as A-frame length, is the distance from the coupler (the part that connects to the tow vehicle) to the front of the trailer body. This measurement impacts turning radius and overall towing stability. It also affects the total length required for storing the trailer.
Interior Dimensions (Enclosed Trailers)
For enclosed trailers, understanding the interior length, width, and height is crucial for determining the usable cargo space inside the trailer. These measurements represent the dimensions of the enclosed area where goods will be stored and transported.
Tools You’ll Need
Measuring a trailer doesn’t require specialized equipment. Here’s a list of tools that will simplify the process:
- Tape Measure: A long tape measure (at least 25 feet) is essential for accurately measuring overall length, width, and deck dimensions.
- Measuring Wheel (Optional): For long trailers, a measuring wheel can provide a more efficient way to measure distances.
- Level: A level is helpful for ensuring accurate height measurements, particularly if the ground is uneven.
- Helper: Having someone assist you can make measuring large trailers significantly easier.
- Notepad and Pen/Pencil: Always record your measurements immediately to avoid forgetting them.
Measurement Tips for Accuracy
Achieving accurate trailer measurements requires attention to detail and a systematic approach. Consider these best practices:
- Park on Level Ground: Ensure the trailer is parked on a flat, level surface before taking any measurements. This will prevent skewed readings, particularly for height.
- Extend the Tape Measure Fully: Always extend the tape measure completely to avoid any slack that could lead to inaccurate readings.
- Measure Multiple Times: Take each measurement at least twice to ensure consistency and identify any potential errors.
- Consider Protrusions: Be sure to include any protruding parts, such as lights, fenders, or ramps, in your overall length, width, and height measurements.
- Round Up (Strategically): In some cases (like buying materials), rounding up to the nearest inch or foot can be beneficial. However, for legal purposes, record the exact measurement first.
Frequently Asked Questions (FAQs) About Trailer Measurement
1. How do I measure the GVWR (Gross Vehicle Weight Rating) of my trailer?
The GVWR is not a measurement that you take. It’s a manufacturer’s specification that is permanently affixed to the trailer, typically on a sticker near the tongue or on the VIN plate. It represents the maximum permissible weight of the trailer when fully loaded. Never exceed the GVWR!
2. What is the difference between deck length and overall trailer length?
Deck length refers only to the length of the trailer bed or platform, while overall trailer length includes the deck length plus the length of the tongue and any protruding parts at the rear.
3. How important is it to measure trailer height accurately?
Extremely important! Inaccurate height measurements can lead to collisions with low bridges or overpasses, resulting in significant damage or accidents. Always measure trailer height precisely and err on the side of caution.
4. Where can I find information about legal trailer length limits in my state?
State transportation departments or departments of motor vehicles (DMVs) typically publish regulations regarding trailer length limits. Search for “[Your State] trailer laws” on their official websites.
5. Do I need to measure the trailer axle position?
Generally, you don’t need to measure the position of the axles for general purposes. However, knowing the axle type (e.g., leaf spring, torsion) and their load capacity can be helpful for maintenance and repair purposes.
6. How does trailer weight affect the required tow vehicle?
The weight of the trailer, especially when loaded, directly impacts the tow vehicle needed. You must ensure your tow vehicle’s towing capacity is sufficient for the trailer’s GVWR. Exceeding the towing capacity can lead to dangerous situations.
7. What is “hitch height” and how do I measure it?
Hitch height is the distance from the ground to the top of the receiver tube on your tow vehicle. This is critical for ensuring a level towing setup. To measure it, park the tow vehicle on level ground and measure from the ground to the top of the receiver opening. You’ll then need to choose a ball mount with the appropriate rise or drop to match the trailer’s coupler height.
8. What should I do if my trailer measurements don’t match the manufacturer’s specifications?
If you notice discrepancies, first double-check your measurements. If the discrepancy persists, contact the trailer manufacturer or a qualified trailer repair shop to investigate further. There might be modifications or alterations that affect the dimensions.
9. How does tongue weight affect towing stability?
Tongue weight is the downward force exerted by the trailer’s tongue on the hitch. It should typically be between 10-15% of the trailer’s total weight. Insufficient or excessive tongue weight can lead to trailer sway and unstable towing.
10. Can I modify the length of my trailer tongue?
Modifying the trailer tongue is generally not recommended without consulting a qualified trailer engineer or manufacturer. Altering the tongue length can affect weight distribution, towing stability, and structural integrity.
11. What are the key differences in measuring an enclosed trailer versus an open utility trailer?
The primary difference is measuring the interior dimensions of an enclosed trailer. You’ll need to measure the length, width, and height of the cargo area inside the trailer, in addition to the overall exterior dimensions. For open trailers, the focus is mainly on deck dimensions and overall external measurements.
12. Where can I find a diagram illustrating common trailer measurement points?
Many trailer manufacturers and online retailers provide diagrams showing the key measurement points, such as overall length, deck length, tongue length, and so on. Search for “trailer measurement diagram” on the internet to find visual aids.