Wondering how to measure draw length without a pro shop visit? Measure your wingspan from fingertip to fingertip, then divide by 2.5. A helper and a tape measure will get you there.
Draw length is one of the first fits to get right, and the rest of your kit is covered in our archery equipment overview.
| Item | Value |
|---|---|
| Wingspan formula | Wingspan ÷ 2.5 = draw length |
| Worked example | 70 inches of wingspan gives a 28 inch draw length |
| Time to measure | About a minute |
| Typical bow adjustment step | Half-inch increments on most bows |
| Wingspan method accuracy | Can come out around 1/4 inch short |
| Bow-side (AMO) measurement | Nock groove to pivot point, plus 1.75 inches |
These figures come from Bowhunter’s draw length guide and a guide from Urban Archery Supplies. Figures and methods can change, so check the sources before you rely on them.
What draw length means
Draw length is the distance from the nocking point on the bowstring, where the arrow sits, to the grip’s pivot point when the string is fully drawn back, as Omni Calculator’s draw length page defines it. In plain terms, it is how far your body lets you pull the string comfortably and the same way every time.
Getting it wrong shows up in your form. If your draw length is too short, you are forced to hunch up to see through your peep sight. If it is too long, you have to stretch and strain to get the string all the way back and hold it there.
Either way, your body ends up in unnatural positions while you aim, and tight arrow groups become hard to shoot. You also lose the classic “T-form” that coaches teach, with your rear (holding) arm in line with the arrow at full draw.
Pro shop owners quoted by Bowhunter say many long-time shooters skip this check. It is most common when people buy used bows or share a bow among friends and family.
How to measure draw length with a helper and a tape
The wingspan method is the easiest way to get started, and it takes about a minute. You need a measuring tape and someone to help you. Work in inches, because that is the easiest unit for this job.
- Stand up straight and spread your arms out wide to the sides.
- Hold that position while your helper measures your wingspan from the fingertip of one middle finger to the other.
- Write the number down in inches.
- Divide that number by 2.5. The result is your estimated draw length.
Here is a worked example. A wingspan of 70 inches divided by 2.5 gives a draw length of 28 inches.
Keep the tape snug but not tight, and ask your helper to check that the tape stays level across your back. A sagging tape adds length that is not really there.
Why the wingspan number is only a starting point
The result should get you very close, though some fine-tuning may still be needed. Urban Archery Supplies says the method is not 100% perfect, but will get you pretty close.
That same guide notes that in its experience the formula result will be a touch short, around 1/4 inch. Treat the number as a first setting, then confirm it by shooting.
The guide also says the best way to settle on a final figure is usually trial and error, sometimes with help from a coach or shop staff. If you are choosing a new bow, your wingspan result gives you a useful rough idea of which size to try first.
Checking your fit at full draw
Once the bow is set close to your number, the real test is how you look and feel at full draw. Bowhunter suggests you ask a friend to stand behind you at full draw and watch your alignment.
Here is what the helper should look for:
- You can pull the string back comfortably and keep good posture.
- Your head is held up straight.
- Your rear (holding) elbow is in line with the arrow and pointing straight away from it.
- You can anchor in a natural, repeatable spot, such as the corner of your mouth or under your jawline.
If one of these is off, your draw length may be a little long or short. Even small adjustments can make a big difference in shooting consistency.
Setting the number on your bow
Most bows let you change draw length in half-inch increments. How you do it depends on your bow:
- With a rotating module, you typically remove a couple of screws, turn the module to the right setting and re-insert the screws.
- With draw-length specific cams, you may need to contact your local dealer to order new cam modules.
- For changes smaller than half an inch, you can use the limb or cable stops on your cams, or change the length of your nocking loop.
If you need a little more length, tie on a longer nocking loop. If you want less, use a shorter one.
The bow itself is measured differently from your body. Under the AMO standard described by Urban Archery Supplies, you measure from the nock groove to the pivot point (the deepest part) of the grip, then add 1.75 inches. For example, 26.25 inches from nock groove to pivot point means a 28 inch draw length bow.
On many bows the pivot point lines up with the arrow rest hole, but not always, so check before you assume.
Draw length, arrows and draw weight
Your draw length also guides arrow length. Omni Calculator says your arrow length should be 1 to 2 inches longer than your draw length, which it ties to safety and performance (see its draw length page).
When you start choosing shafts, read up on arrow spine so the stiffness suits your setup.
Draw length describes how far you pull. For how hard you pull, see the guide to bow draw weight.
Frequently asked questions
What is my draw length if my wingspan is 100 inches?
Show answer
Divide 100 by 2.5 and you get a draw length of 40 inches, according to Omni Calculator’s worked example.
Is the wingspan formula exact?
Show answer
No. It gets you close, but the Urban Archery Supplies guide says the result can be a touch short, around 1/4 inch. Use it as a starting point and fine-tune from there.
How can I make a small draw length change?
Show answer
For changes under half an inch, adjust the limb or cable stops on your cams or change the nocking loop length. A longer loop adds draw length and a shorter one takes it away.
How is draw length measured on the bow itself?
Show answer
The AMO method measures from the nock groove to the grip’s pivot point and adds 1.75 inches. A reading of 26.25 inches means a 28 inch draw length bow.
