Measuring and calculating your draw length accurately allows you to set up your bow correctly by helping you optimize your anchor points, d-loop, peep sight, and bow sight, and setting the optimal arrow length for your bow. It also gives you the data you need to calculate bow and arrow speed. In just 3 quick steps you can use the Compound Bow Draw Length Calculator below and start your archery journey off right. Watch the video below for a more detailed description and demonstration.
Knowing your proper draw length allows you to ensure the bow is optimized for you when you are at full draw with a bow. You don’t want to pull the string back and have it too short and you definitely don’t want it to be too long. This allows you to set up the proper location of your peep sight and bow sight for perfect sight alignment and positioning.
Plus, you must know it when buying a new bow because every bow has specific draw length ranges and limits. Plus, you can’t set up a bow without knowing your exact measurements.
The calculator below will get you close. Just remember that even if you measure perfectly, you may have to adjust the draw length on your bow slightly. In most cases, it is recommended that you go to your local Archery Pro Shop and have an expert there set things up for you.
The Draw Length Formula
The calculator here uses the formula: wingspan/2.5 (wingspan is measured in inches)
This formula tends to get closer to the exact draw length for most people as you don’t want to have your anchor point too far back towards your ear. The anchor point for your draw should be closer to the corner of your mouth, mid-cheek on your shooting side. You should also be able to touch the tip of your nose to the bowstring while simultaneously looking through your peep sight and bow sight.
For most, the formula listed here will give them exactly what they need. It is very dependent on your individual wingspan measurements. The form below will give the exact draw length number, but you will have to round to the nearest half-inch (always round down to the nearest half-inch increment, rounding up is not recommended).
Bows usually advertise different allocations of draw lengths. For example, a bow may advertise a range of 26″ to 30″ in half-inch increments. Knowing what your specific draw length is will allow you to know what bows are available in your specific length. Either way, it is always important to check this at your local Archery Shop to ensure the best fit possible before you buy and then tune your bow.
In addition, it is important to know that the way your grip hand grips the bow can add or subtract from what you measure here. If you stretch and really push out on your grip this can lengthen it and if you use a collapsed wrist style grip, this can shorten it. In most cases this is minimal, but it is a consideration and might explain if you need to make adjustments to your bow.
Please remember that the release aid you use could impact your draw length. A standard mechanical release will normally work just fine with the calculator here. If you use a finger-style or hook-type release where your trigger is engaged with your thumb instead of your trigger finger; you may have to adjust your draw length (But in most cases other adjustments can and should be made instead).
See our List of Archery Calculators below:
How to Calculate Your Draw Length
Calculating your draw length is easy and only requires three quick steps. Follow the 3 steps below and you will be ready to buy and/or set up your Compound Bow!
Step 1: Measure Your Wingspan
Stand with your back flat against a wall and stretch your arms extended to your sides, with your hands and fingers extended (as shown in the picture above – DO NOT stretch for a larger measurement). Then measure the distance, in inches, from the tip of your middle finger on one hand to the tip of your middle finger on the other. This will measure your total wingspan in inches. Watch the video above to see how this is done.
Step 2: Calculate Base Draw Length
Take the total wingspan measurement from Step 1 (in inches) and divide that number by 2.5. For example, my total wingspan is 68 inches. 68/2.5 = 27.2. My base draw length is now estimated to be 27.2 inches.
Step 3: Round Down to Nearest Half-Inch
Now, you should round down to the closest half-inch. As stated in Step 2, my base draw length is calculated to be 27.2 inches. I now round this total down to 27.
My Draw Length is now set at 27 inches.
It is recommended to round down as it is easier to work with a slightly shorter draw and add to the length of your d-loop than to have a draw that is hard to adjust your shooting arm with. A longer than optimal length can lead to issues with your shot cycle, fundamentals, and shooting mechanics
Always work with an Archery Professional to ensure your draw length is sized perfectly to you and your release aid type. Rounding can change your best possible draw length slightly depending on your body type.
Now you are ready to buy or set up your new bow to your personal draw length.
To calculate your draw length fast, enter your wingspan measurement (in inches) into the calculator below now.
How do I find the draw length of a compound bow?
If you have a compound bow and do not know what the current draw length is set to, remember that the draw length on a bow is measured from the nocking point on the string to the throat of the grip (the deepest part of the grip) plus 1.75 inches when at full draw. In addition, some bows have settings displayed on the bow’s cams. This is sometimes displayed in single digits and may vary from bow to bow.
Does draw length affect arrow speed?
Yes, your arrow’s speed is increased with every half-inch of draw length and decreased as draw length decreases. This is due to the bow not being drawn to its fully optimized length. If your draw length matches the bow’s maximum, then this is not a factor for that specific bow. To see all the factors that affect arrow speed, check out the Arrow Speed, Kinetic Energy, and Momentum calculator here.
Why is knowing my draw length important?
Compound bows are sold in specific draw lengths. These are set so they can fit your specific measurements and allow for a perfect length at full draw and maximize your ability to shoot the bow accurately. This is all critical when choosing or buying a bow and critical when choosing and setting up your arrows. Plus, by setting your draw length correctly, you can properly align your peep sight and bow sight, ensuring a more accurate shooting profile for you and your bow.
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