By Zencalcy Editorial TeamLast reviewed About us
Draw length is the distance from the nock point to the grip at full draw. A common starting estimate divides arm span by 2.5. The result is a fitting baseline for a bow, not a substitute for a pro-shop measurement.
Find archery draw length from arm span.
Draw length (in) = arm span (in) ÷ 2.5 Draw length (cm) = arm span (cm) ÷ 2.5
The 2.5 divisor is a widely used archery fitting shortcut. Actual draw length also depends on shooting style, release type, bow design and comfort. Compound bows are usually set slightly shorter than the estimate; traditional bows may use a different reference.
| Symbol | Meaning |
|---|---|
| Arm span | Fingertip-to-fingertip distance with arms horizontal. |
| 2.5 | Empirical divisor used to convert wingspan to draw length. |
178 ÷ 2.5 = 71.2 cm, or 28.0 inches. A 180 cm span gives 72 cm (28.3 in), which is often rounded to a 28-inch draw for a compound bow.
Draw length sets the geometry of the shot. If it is too long, the archer overextends, collapses the shoulder and loses consistency; if it is too short, the bow feels cramped and the release is cramped against the face. The arm-span shortcut works because wingspan and draw length scale together in most adults, but it ignores shoulder mobility, hand size, anchor point and shooting style. A compound bow with a release aid typically fits a slightly shorter draw than the same archer would use with fingers on a recurve. The practical approach is to start with the estimate, then confirm with a bow set up at that length and a few test draws. Changing draw length later is possible on many compound bows but affects draw weight and tuning, so getting it close before purchase saves time and money.
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For many adults the two are close, but arm span can differ by several centimetres. Measure the span directly if you can.
Every result is a screening estimate from published anthropometric equations, not a diagnosis or a measurement of body composition. Tape measurements should be taken snugly against the skin without compressing it, at the landmarks named in each tool. Equations were derived in specific populations and can be less accurate for athletes, older adults, children, pregnant people and people with significant oedema.
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Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026