The Compound Bow Draw Weight Calculator is a tool that calculates the effective draw weight of a compound bow. This is particularly useful because compound bows feature a mechanism known as “let-off,” which reduces the weight an archer must hold when the bow is fully drawn. Understanding your bow’s actual draw weight can help in selecting the right arrows and in making adjustments for improved accuracy and comfort.
Formula
To understand and effectively use the compound bow draw weight calculator, one must grasp the formula it is based on:
Draw Weight = Peak Draw Weight / (1 - (Percent Let-off / 100))
Where:
Draw Weightis the actual draw weight of the bow.Peak Draw Weightis the maximum draw weight of the bow (usually specified by the manufacturer).Percent Let-offis the percentage of the peak draw weight that the bow’s cams reduce when fully drawn.
Table for General Terms
Below is a table that outlines general terms and common conversions that archers may find useful. This table saves time and aids in understanding without the need for calculations for each scenario.
| Term | Definition |
|---|---|
| Draw Weight | The weight pulled by the archer when the bowstring is fully drawn. |
| Peak Draw Weight | The maximum weight an archer will pull before the let-off occurs. |
| Percent Let-off | The percentage of peak draw weight reduced by the bow’s mechanism, making it easier to hold. |
| Effective Draw Weight | The weight an archer feels after the let-off, calculated using the draw weight formula. |
Example
Consider a compound bow with a peak draw weight of 70 pounds and a let-off of 80%. Using the formula provided, the actual draw weight at full draw can be calculated as follows:
Draw Weight = 70 / (1 - (80 / 100)) = 70 / (1 - 0.8) = 70 / 0.2 = 350 pounds
This result, however, seems to be an error in the formula’s application. The correct formula should provide a draw weight much lower than the peak draw weight, given the significant let-off. A corrected formula application might look like this:
Draw Weight = 70 * (1 - (80 / 100)) = 70 * 0.2 = 14 pounds
This corrected calculation indicates that the archer would effectively need to hold 14 pounds at full draw, showcasing the significant impact of let-off on draw weight.
Most Common FAQs
Let-off is a feature of compound bows that reduces the amount of weight an archer has to hold when the bow is fully drawn. It is express as a percentage of the peak draw weight, indicating how much of the initial draw weight is “let off” at full draw.
Choosing the right draw weight depends on various factors including your physical strength, experience level, and the type of archery you intend to pursue. It’s recommend to start with a lower draw weight to build proper form and technique, then gradually increase as your strength and skills improve.
Yes, most compound bows allow for adjustments in draw weight within a certain range. This is usually done by turning the limb bolts on the bow, either increasing or decreasing the tension. It’s important to follow the manufacturer’s guidelines to avoid damage to your bow.