What Is The Let-off In A Compound Bow, And Why Is It Important?

Imagine this: you’re standing in the middle of a vast expanse of green fields, with the sun warming your skin and a gentle breeze rustling through the trees. In your hands, you hold a compound bow, ready to take aim and release an arrow with pinpoint precision. But have you ever wondered what exactly is happening behind the scenes when you release that arrow? This is where the let-off in a compound bow comes into play. In this article, we’ll break down what let-off is, how it affects your accuracy, and why it’s an important factor to consider when choosing your perfect bow. So, grab your bow, let’s dive right in!

What is the let-off in a compound bow?

The let-off in a compound bow refers to the reduction in the weight you have to hold back when fully drawn, compared to the peak weight of the bow. This reduction in weight occurs when the cam system on a compound bow reaches its maximum rotation or let-off point. The let-off percentage is a crucial factor in determining the efficiency and performance of a compound bow.

Definition of let-off

Let-off is defined as the difference between the peak weight and the holding weight of a compound bow. It is expressed as a percentage, and it represents the amount of weight the archer must hold at full draw. For example, if a compound bow has a let-off of 80%, and the peak weight is set at 60 pounds, the holding weight would be 12 pounds.

Mechanism of let-off

The let-off mechanism is achieved through the unique design of the cams or wheels on a compound bow. When you draw the bowstring back, the cams rotate, creating a change in the tension of the bowstring and cables. As the cams rotate, the draw weight decreases, allowing you to hold the bow at full draw without exerting the same amount of effort required to draw the bow.

Components involved in the let-off

The main components involved in the let-off of a compound bow are the cams or wheels, bowstring, cables, and the draw stop or wall. These components work together to create the let-off effect, reducing the holding weight and making it easier for the archer to aim and hold the bow steady.

Why is the let-off important?

The let-off in a compound bow offers several advantages that make it an essential factor to consider when choosing a bow. These advantages include improved accuracy, reduced holding weight, easier aiming, and increased hunting efficiency.

Improved accuracy

The let-off plays a crucial role in improving accuracy because it allows the archer to hold the bow steady and focus on aiming without the strain of holding a heavy weight. With less muscle fatigue, you can maintain a more consistent aim, resulting in more accurate and consistent shots.

Reduced holding weight

One of the primary benefits of let-off is the reduction in the weight you have to hold at full draw. This reduced holding weight makes it easier to maintain the draw position for an extended period, allowing you to take your time to aim and make precise shots. It also helps prevent muscle fatigue, enabling you to shoot multiple arrows without losing strength or accuracy.

Easier aiming

By reducing the holding weight, the let-off provides a more stable platform for aiming. With less effort required to hold the bow at full draw, you can focus on aligning your sight or target pins, adjusting for windage and elevation, and executing a smooth release. This easier aiming process enhances your overall shooting experience and increases your chances of hitting the target consistently.

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Increased hunting efficiency

For bowhunters, the let-off is especially important as it allows you to hold the bow at full draw for an extended period while waiting for the perfect shot opportunity. This increased holding time enhances your chances of making a well-placed shot on your target without the bowstring exerting unwanted pressure on your muscles. The let-off also reduces the chances of getting fatigued during a critical hunting situation, ensuring you can make the shot accurately when the moment arises.

What Is The Let-off In A Compound Bow, And Why Is It Important?

Understanding the let-off percentage

The let-off percentage is a crucial specification to consider when selecting a compound bow. It determines the amount of weight reduction at full draw and plays a role in the bow’s overall performance.

Calculation of let-off percentage

The let-off percentage is calculated by dividing the difference between the peak weight and the holding weight by the peak weight and then multiplying by 100. For example, if the peak weight is 70 pounds and the holding weight is 14 pounds, the let-off percentage would be 80%.

Let-off Percentage = (Peak weight - Holding weight) / Peak weight * 100 

Common let-off percentages

Compound bows typically have a let-off percentage ranging from 65% to 90%, with 70% and 80% being the most common. Higher let-off percentages provide more weight reduction at full draw, making it easier to hold the bow steady. However, higher let-off percentages may sacrifice some arrow speed and power stroke length.

Choosing the appropriate let-off percentage

The choice of let-off percentage depends on various factors, such as your shooting style, physical strength, and the purpose of the bow. If you prioritize comfort, accuracy, and ease of aiming, a higher let-off percentage would be suitable. However, if you value arrow speed and power, a lower let-off percentage may be more appropriate. It is essential to try different let-off percentages and consult with experienced archers or bow technicians to find the optimal balance between comfort and performance.

The impact of let-off on bow performance

The let-off percentage has a significant impact on several aspects of a compound bow’s performance, including arrow speed and momentum, power stroke length, energy efficiency, and shot noise and vibration.

Arrow speed and momentum

A higher let-off percentage typically results in a slight decrease in arrow speed compared to a lower let-off percentage. This is because the energy required to propel the arrow is reduced as the draw weight decreases at full draw. However, the difference in arrow speed between different let-off percentages is minimal and often outweighed by the advantages of a higher let-off in terms of accuracy and ease of aiming.

Power stroke length

The power stroke length refers to the distance the bowstring travels from its resting position to full draw. A higher let-off percentage decreases the power stroke length because the cams reach their maximum rotation earlier in the draw cycle. This reduction in power stroke length affects the efficiency of the bow and can have an impact on arrow speed and kinetic energy.

Energy efficiency

The let-off percentage influences the energy efficiency of a compound bow. Higher let-off percentages typically result in slightly lower energy efficiency due to the reduced draw weight at full draw. However, the trade-off is often worth it for archers who prioritize comfort and accuracy, as the benefits of easier aiming and reduced muscle fatigue outweigh the slight decrease in energy efficiency.

Shot noise and vibration

The let-off percentage can also affect shot noise and vibration. A higher let-off percentage generally results in reduced noise and vibration upon release, as the reduced holding weight minimizes the chance of the bow transmitting unwanted vibrations. This can lead to a quieter and smoother shooting experience, which is particularly important for hunting situations where stealth is crucial.

What Is The Let-off In A Compound Bow, And Why Is It Important?

Factors influencing the let-off

Several factors can influence the let-off of a compound bow, including cam design, draw length, bow weight, string and cable materials, and tuning and maintenance.

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Cam design

The design of the cams or wheels on a compound bow plays a significant role in determining the let-off percentage. Different cam designs can provide different let-off percentages and affect the force-draw curve of the bow. Some cam systems offer a modular design, allowing archers to adjust the let-off percentage by changing modules or rotating the cams.

Draw length

The draw length of a compound bow is the distance from the bowstring at rest to the bowstring when fully drawn. The let-off percentage can vary depending on the draw length. As the draw length increases, the let-off percentage may decrease or become less efficient due to the change in leverage and string angle. It is crucial to select a draw length that suits your physique and shooting style to optimize the let-off and overall performance of the bow.

Bow weight

The overall weight of the compound bow can influence the let-off percentage. Lighter bows often have higher let-off percentages, as the reduced weight makes it easier to hold the bow steady at full draw. Conversely, heavier bows may have slightly lower let-off percentages, but they may provide additional stability and reduce hand torque during the shot.

String and cable materials

The materials used for the bowstring and cables can affect the let-off percentage. Different string materials and construction techniques can create variations in the force-draw curve and let-off efficiency. It is essential to use high-quality, properly maintained strings and cables to ensure optimal performance and consistent let-off.

Tuning and maintenance

Proper tuning and regular maintenance of the compound bow are essential for achieving and maintaining the desired let-off percentage. Incorrectly tuned cams, worn out cables, or a lack of lubrication can affect the smoothness of the draw cycle and the let-off efficiency. Regular inspections, adjustments, and lubrication can help ensure consistent let-off performance and prolong the lifespan of the bow.

Let-off and archery styles

The let-off percentage can have different implications across various archery styles, including target archery, bowhunting, 3D archery, and bowfishing.

Target archery

In target archery, where precision and accuracy are paramount, a higher let-off percentage is often preferred. The reduced holding weight allows for better stability during the aiming process and helps maintain a steady hand for consistent shots. The comfort and ease of aiming provided by a higher let-off percentage allow archers to focus on executing proper form and achieving tight arrow groupings.


For bowhunters, the let-off percentage is crucial as it directly impacts their ability to hold the bow at full draw while waiting for the perfect shot opportunity. A higher let-off percentage enables bowhunters to hold their position longer, increasing their chances of making an accurate shot. However, the specific let-off percentage chosen may also depend on factors such as the required arrow speed, desired energy for ethical kills, and personal shooting preferences.

3D archery

In 3D archery, where archers shoot at realistic, three-dimensional animal targets, the let-off percentage can vary depending on personal preference and the specific course layout. Some archers may prefer a higher let-off to enhance stability and accuracy, while others may opt for a lower let-off to maximize arrow speed and penetration on simulated hunting scenarios. It ultimately comes down to finding the right balance between comfort, accuracy, and performance.


Bowfishing is a unique archery style where archers shoot at fish in a water environment. In bowfishing, the let-off percentage is not as critical as in other archery styles, as quick shots and shot recovery are essential. Archers often opt for lower let-off percentages to maintain a quicker draw cycle and minimize the time spent aiming and holding the bow at full draw. The focus is on fast reaction time and accuracy, as fish movements can be unpredictable.

Adjusting the let-off on a compound bow

Although the let-off percentage is typically set by the manufacturer, there are several ways to adjust it to suit your shooting style and preferences.

Changing the draw length

Adjusting the draw length can indirectly affect the let-off percentage. By increasing or decreasing the draw length, you can influence the leverage and string angle, which can alter the let-off efficiency. However, it is crucial to consult with experienced archers or bow technicians to ensure proper adjustments are made without compromising the bow’s performance or safety.

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Switching cams or modules

Some compound bows offer modular cam systems that allow you to change the let-off percentage by swapping out modules or rotating the cams. This feature provides flexibility in adjusting the let-off without requiring specialized tools or extensive maintenance. However, it is important to follow the manufacturer’s guidelines and consult with professionals if you are unfamiliar with the process.

Adjusting the draw weight

Although adjusting the draw weight directly affects the peak weight of the bow, it can indirectly influence the let-off percentage. By reducing or increasing the draw weight, you can impact the holding weight at full draw and potentially adjust the let-off percentage. However, it is crucial to make adjustments gradually and ensure the bow remains safe and within its recommended specifications.

Modifying string and cables

Modifying the string and cables can also have an indirect effect on the let-off percentage. Switching to different materials or adjusting the lengths of the strings and cables can alter the draw cycle and let-off efficiency. However, it is important to seek professional assistance or follow manufacturer’s guidelines to ensure proper modifications are made without compromising the bow’s performance or safety.

Professional assistance

If you are unsure about adjusting the let-off percentage yourself or if you want to fine-tune your compound bow’s performance, it is always recommended to seek professional assistance. Experienced archery technicians can help you adjust the let-off, ensure proper bow tuning, and provide valuable advice based on your specific needs and shooting style.

Safety considerations with let-off

While let-off offers numerous advantages, it is essential to pay attention to safety considerations to ensure a safe and enjoyable archery experience.

Risk of accidental firing

With the reduction in holding weight at full draw, it is crucial to maintain control over the bow and avoid accidental releases. Proper finger or mechanical release techniques should always be followed to prevent premature or unintentional firing of the bow. It is also important to maintain a safe direction and never point the bow or draw it toward anyone or anything that you do not intend to shoot.

Proper bow handling

As with any archery equipment, proper bow handling is essential for safety. Always carry the compound bow with the arrow pointed downward or parallel to the ground. Avoid placing your fingers or any objects near the bowstring when drawing or letting down the bow. Maintain a safe distance from others while shooting to prevent accidental injuries.

Ensuring correct equipment setup

To ensure safety, it is vital to have your compound bow correctly set up and well-maintained. Regularly inspect the bowstring, cables, cams, and other components for signs of wear or damage. Make sure all fasteners are tight, and any necessary adjustments or repairs are made by qualified professionals. Properly adjusting the let-off percentage and other settings of the bow can help prevent malfunctions or accidents during shooting.

Common misconceptions about let-off

There are several common misconceptions regarding the let-off in a compound bow that are worth clarifying.

Let-off as a substitute for proper form

Although the let-off percentage can make it easier to hold the bow steady and aim, it should not be seen as a substitute for proper shooting form. Proper shooting techniques, including stance, grip, and form, are crucial for accuracy and consistency. The let-off should be seen as a tool that enhances your shooting experience rather than a replacement for proper archery fundamentals.

Increased accuracy without practice

While the let-off can contribute to improved accuracy by reducing muscle fatigue and allowing for easier aiming, it does not guarantee accuracy without proper practice and training. To shoot accurately, it is important to develop a consistent form, work on your aiming technique, and practice regularly. The let-off can provide a more stable platform for accuracy, but it is still up to the archer to develop the necessary skills.

Let-off and hunting success

Although let-off can enhance hunting efficiency by allowing for longer holding times and reduced muscle fatigue, it should not be seen as a guarantee of hunting success. Successful hunting requires a combination of factors, including proper shot placement, stealth, knowledge of wildlife behavior, and practice under realistic hunting conditions. The let-off can assist in making accurate shots, but it is ultimately the archer’s skill and decision-making that determine hunting success.


The let-off in a compound bow is a crucial factor that significantly impacts its performance and the shooting experience of the archer. It provides advantages such as improved accuracy, reduced holding weight, easier aiming, and increased hunting efficiency. Understanding the let-off percentage, its impact on bow performance, and the factors that influence it can help archers make informed decisions when selecting and adjusting compound bows. By prioritizing safety, proper handling, and regular maintenance, archers can fully enjoy the benefits of let-off while maximizing their shooting potential. So, whether you’re a target archer, bowhunter, or engaged in other archery styles, the let-off is an essential consideration for optimizing your archery experience.

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