How To Find Draw Length For Recurve Bow

Basically your draw length is how far you pull the string back. The Archery Trade Association (ATA), formally the Archery Manufactures and Merchants Organization (AMO), is responsible for publishing archery related standards. The ATA defines draw length as "the distance, at archer's full draw, from nocking point on string to the pivot point of the grip, plus 1 3/4 inches ".

The are a couple of important safety issues related to your draw length.
The first is arrow length. If you do not know your draw length and you try to shoot an arrow that is too short you may end up drawing the arrow beyond the rest or the shelf which can be very dangerous. It is important to make sure your arrow length is longer that your draw length . The length of the arrow also determines the dynamic spine of the arrow, ideally you want the arrow to be just the right length so that it will tune correctly and shoot straight.
The second is overdrawing the bow. If you shoot a recurve bow that is too short for your draw length, you may end up bending the limbs beyond their tolerance and they can break. Every bow has a specific draw length that it will perform most efficiently at. Ideally you want to find a bow length that will perform best with you draw length.

Beyond these safety issues, your draw length is also important to know when determining your actual draw weight, and setting up a compound bow for the first time

How to find your draw length

With a recurve, the best way to find your draw length is to use a measuring arrow. Place a piece of masking tape on your bow just above the arrow rest/shelf. Draw a vertical line on the tape that is directly above the pivot point of the grip. Nock the measuring arrow on your bow, and draw back to your anchor. Have a helper read the measurement at the vertical line. Do this a couple times to make sure the measurement is consistent and accurate. Finally add 1 3/4″ to the measurement and you now have your ATA draw length.

If you do not have a measuring arrow you can have a helper put a mark on a normal arrow directly above the pivot when you are at full draw. Measure from the valley of the nock to the mark then add 1 3/4″ to get your ATA draw length.

To determine your draw length without a bow, you can use the following calculated draw length:

With your arms stretched straight out to your sides, measure from the tip of one middle finger to the tip of the other middle finger. This is your wingspan. For many people, wingspan is generally the same length as height. To get your draw length, divide your wingspan by 2.5

Wingspan / 2.5 = Draw Length

This calculation is not exact, your draw length my vary slightly from the number you get, but it will get you a figure that can help you approximate appropriate bow length, safe arrow length, and compound bow draw length.

Using your draw length to determine your actual draw weight

The draw weight listed on the limbs of your bow is the ATA draw weight . For standardization purposes, the ATA draw weight is weighed and marked at a 28" draw length . If you do not have a 28″ draw length, your actual draw weight will differ from what is marked on the bow.

The best way to find your actual draw weight is with a bow scale . Again, place a piece of masking tape on your bow just above the arrow rest/shelf. Draw a vertical line any where on the tape. Nock an arrow and draw back to your anchor. Have a helper mark the arrow at the vertical line, then let down slowly. Now, attach the bow scale to the string and draw the bow using the same arrow until the mark on the arrow lines up with the vertical line on the tape then let down slowly. Check the bow scale for your actual draw weight.

To determine draw weight of a "conventional" recurve bow with out a bow scale , you can use the ATA draw weight calculation formula:

Divide the bow's ATA draw weight by 20 (ATA recommends a factor of 20), then multiply by the number of inches your draw length differs from 28". Finally subtract or add this amount to the bow's listed draw weight if your draw length is shorter or longer respectively.

Examples:

Bow Weight = 42 lbs, Draw length = 25.5" (2.5" shorter than 28)

42 lbs ÷ 20 = 2.1 lbs
2.1 lbs x 2.5" = 5.25 lbs

42 lbs – 5.25 lbs (subtract because draw length is shorter than 28″) = 36.75 lbs
The actual draw weight at 25 1/2″ is 36.75 lbs

Bow Weight = 38 lbs, Draw Length = 30" (2" longer than 28)

38 lbs ÷ 20 = 1.9 lbs
1.9 lbs x 2 = 3.8 lbs.

38 lbs + 3.8 lbs (add because draw length is longer than 28″) = 41.8 lbs
The actual draw weight at 30″ is 41.8 lbs