How to Measure Draw Length Accurately
Measure your wingspan fingertip to fingertip in inches and divide by 2.5, rounding to the nearest half inch. A 70 inch wingspan gives a 28 inch draw length. Confirm that estimate at full draw with a marked arrow, because form and anchor style move the true number by up to an inch.
Draw length is the first measurement in archery and the one most often wrong. A bow set even half an inch too long changes everything downstream: your anchor, your arrow spine, your sight marks and your ability to tune. It is worth 20 minutes to get right, and it is worth rechecking after your first serious month of shooting, because form changes as you learn.
Method 1: the wingspan formula
Stand relaxed against a wall with your arms out to the sides, level with your shoulders, palms facing forward. Do not stretch or reach. Have someone measure from the tip of one middle finger to the tip of the other, then divide by 2.5 and round to the nearest half inch.
A 67.5 inch wingspan gives 27 inches. A 70 inch wingspan gives 28. A 75 inch wingspan gives 30. Note that wingspan is usually close to height but not identical, and the difference between the two is exactly why the formula uses wingspan. Long-armed shooters get a longer draw than their height suggests, and short-armed shooters get a shorter one. The draw length calculator does the arithmetic and rounds it for you.
| Wingspan | Draw length | Typical arrow length | Notes |
|---|---|---|---|
| 60 in | 24 in | 25 to 26 in | Youth range, look for adjustable cams |
| 65 in | 26 in | 27 to 28 in | Common for smaller-framed adults |
| 67.5 in | 27 in | 28 to 29 in | Very common adult setting |
| 70 in | 28 in | 29 to 30 in | The most common adult draw length |
| 72.5 in | 29 in | 30 to 31 in | Check that your bow model reaches this |
| 75 in | 30 in | 31 to 32 in | Near IBO reference draw, spine gets weak fast |
| 77.5 in | 31 in | 32 to 33 in | Limited bow selection, expect stiffer spine |
Method 2: the marked arrow, which is the one that counts
The formula gives you a starting point. This gives you the answer. Take a long uncut arrow and a bow you can safely draw, come to full draw with a natural anchor, and have a helper mark the shaft where it crosses the front of the riser shelf. Measure from the throat of the nock to that mark, then add 1.75 inches to convert to the ATA standard that bow manufacturers print on their spec sheets.
Do this with a relaxed bow arm, not a locked one. Do it three times across three separate draws and take the average, because the first draw of the day tends to be the longest and the least representative. If the three marks are spread over more than about half an inch, your anchor is not yet consistent and the answer will move as your form settles. Work on the form fundamentals first and remeasure.
How to tell your current draw length is too long
Too long is the default error, partly because shops fit quickly and partly because a longer draw feels powerful and produces more speed. Watch for these symptoms, which all point the same way:
- String slap on the forearm. The classic sign. A correct draw length lets the bow arm rotate the elbow crease out of the string path without conscious effort.
- Locked bow elbow. If your bow arm has to hyperextend to reach the wall, you are too long. A slight bend should be available.
- Release hand floating off the face. The anchor should be a hard contact point, not a hover.
- Head pushed forward toward the string. Your head should stay upright and the string should come to you.
- Peep alignment that changes shot to shot. A moving anchor moves the peep, and no amount of tuning fixes it.
Shortening a compound half an inch usually fixes all five at once. You will lose roughly 5 fps. That is an excellent trade.
Why the number matters beyond comfort
Arrow spine. Draw length sets arrow length, and every extra inch of arrow weakens dynamic spine by about one spine group. Get draw length wrong and you buy the wrong shafts. Enter your finished numbers into the arrow spine calculator only after this measurement is settled.
Speed. IBO speed ratings are measured at a 30 inch draw with 70 pounds and a 350 grain arrow. Below 30 inches, expect to lose roughly 10 fps per inch. A 28 inch shooter is already about 20 fps under the number on the sticker before arrow weight is considered.
Bow fit. Not every bow covers every draw length, and cams have a sweet spot in the middle of their range. A bow adjusted to the extreme end of its module range often draws harder and rolls over less cleanly than one running mid-range.
Draw length for growing archers
A young archer's draw length changes every season, sometimes twice. Buying a bow with a wide module range, something covering roughly 19 to 29 inches, is far more useful than buying a bow that fits perfectly right now. Remeasure at the start of each season and check the arrow length at the same time, because arrows that were correct last year are now short enough to matter.
Safety: never draw a bow whose draw length is set far longer than yours to "see if you can reach it". Overdrawing past the cam stop, or letting the string slip while stretched to reach, risks both injury and a dry fire that can destroy the bow. Have draw length changes and cam module swaps done or checked at a pro shop.
After you have the number
- How to set draw weight: the other half of bow fit
- First bow setup checklist: everything in order
- How to tune a compound bow: draw length is step zero of tuning
- Arrow speed calculator: see what your real draw length does to IBO speed
Frequently asked questions
What is the wingspan formula for draw length?
Stand with arms out level, palms forward, and measure fingertip to fingertip. Divide that number in inches by 2.5 and round to the nearest half inch. A 70 inch wingspan gives 28 inches of draw length. The formula is a starting point rather than a verdict, because shoulder width, neck length and anchor style all shift the true number by up to an inch either way.
How is compound draw length actually defined?
The industry standard, set by ATA, measures from the throat of the nock at full draw to the pivot point of the grip, plus 1.75 inches. That extra 1.75 inches exists so the number roughly corresponds to the old back-of-riser measurement. This matters because a bow marked 28 inches is measured to that standard, and a shop measuring you a different way will give you a different answer.
What happens if my draw length is too long?
You will lock the bow arm straight, push the head forward to reach the string, and hold the release hand away from the face instead of anchored on it. The results are a slapped forearm, an inconsistent anchor, and a bow that will not tune because your form changes shot to shot. Too long is by far the more common error and the more damaging one.
What happens if my draw length is too short?
Short draw feels comfortable and controllable, which is why some shooters end up there deliberately, but it costs speed because you are using less of the power stroke, and it crowds the release hand into the face. Roughly speaking a bow loses about 10 fps per inch of draw length. A half inch short is a reasonable trade for better form. Two inches short is not.
Should recurve and compound draw length be the same?
Close but not identical. Recurve archers usually draw slightly longer because there is no let-off holding wall and the anchor tends to sit further back under the jaw with a finger release. Compound draw length is fixed by the cam and forces a specific position, so it should be set to where your form is repeatable rather than to the longest position you can reach.
Can I adjust draw length myself?
On many modern bows yes, through a rotating module or a set of screw positions on the cam, and that adjustment needs only an Allen wrench. Older bows and some flagship cams need a cam swap or a bow press. Whenever you change draw length, recheck cam timing, nocking point and sight marks, because all three move with it.
How we choose: we compare published manufacturer specifications, verified owner reviews, and pro shop guidance. We do not test gear in person. Draw weight and arrow spine affect safety, so follow your bow manufacturer's specifications and have setup work checked by a qualified pro shop.