Draw Length Calculator

Draw length is how far you pull the bowstring back at full draw, measured on a standard scale that bow makers use. Measuring it at full draw is most accurate, but a simple arm span rule gets most people close enough to start.

What Draw Length Measures

It is a fit measurement, like a shoe size for your bow. It tells you which draw length setting a compound bow needs and how long your arrows should be², and it changes how much a recurve pulls at full draw⁶. It does not tell you how strong you are or what draw weight to use.

The Formula

Draw length (in) = arm span (in) / 2.5

Fallback: draw length (in) = height (in) / 2.5

Draw length to pivot point = ATA draw length - 1.75 in

The arm span rule is the one archery shops use. Lancaster Archery and the Archery Trade Association's Archery 360 both tell archers to divide their wingspan by 2.5¹ ². The height version works because adult arm span is usually close to height⁴, and a published height to draw length chart matches height / 2.5 on every row⁵.

How This Calculator Computes Your Result

Choose inches or cm and enter your arm span. If you cannot measure it, leave it empty and enter your height instead (you can type feet and inches, such as 5'10"). We divide by 2.5, then round to the nearest half inch, because compound bow modules adjust in quarter or half inch steps⁷. You also see the unrounded value in inches and cm, your draw length to the grip's pivot point, a suggested target recurve length, and what your draw means for a recurve's marked weight. If you enter both numbers, arm span is used and height is shown for comparison.

What Your Result Means

For adults from about 5 ft 3 in to 6 ft 6 in, the rule gives roughly 25 to 31 inches. A typical draw length for a child under 10 is 19 to 23 inches⁸. The recurve lengths come from Lancaster Archery's chart for target archers¹.

Treat your number as a starting point, and fine tune it by shooting².

How to Measure Correctly

You need a helper and a tape measure.

• Stand tall and stretch your arms straight out to the sides at shoulder height, making a "T" shape¹ ².

• Do not stretch or reach. Lancaster's advice is to extend your arms naturally¹.

• Have your helper measure from the tip of one middle finger to the tip of the other¹.

• Measure twice and use the average.

Every inch of arm span changes the estimate by 0.4 inches, so drooping arms or bent elbows matter. If your arm span is much longer or shorter than your height (a high or low ape index), use arm span, not height.

The ATA (AMO) Draw Length Standard

Bows are labeled using the standard of the Archery Trade Association (ATA), formerly called the AMO. The ATA draw length is the distance from the string to the pivot point of the grip at full draw, plus 1 3/4 inches³. The extra 1 3/4 inches stands for the average distance from the far side of the bow to the grip's pivot point³. So a 28 inch ATA draw length is 26.25 inches to the pivot point. This calculator shows both numbers.

Draw Length on a Compound vs a Recurve Bow

A compound bow has a mechanical stop set to one draw length, and its cams decide what that is². Some bows use a module for each draw length, while others have adjustable modules that cover a range such as 25 to 30 inches⁷. Being an inch too long or short can cause problems from poor accuracy to injury², so a compound must be set to your number.

A recurve has no stop⁸, and its weight keeps rising as you pull. Recurve limbs are labeled at a 28 inch draw⁶. Past 28 inches, the weight climbs by roughly 2 to 3 pounds per inch⁶. For example, 44 pound limbs drawn to 29.5 inches pull about 47 to 48.5 pounds. If your draw is under 28 inches, you pull less than the label.

Bow length matters too. Drawing a short recurve too far makes the weight rise sharply, so longer draws need longer bows¹.

Choosing a Starting Draw Weight

This calculator does not give a draw weight, because we found no table by age and body weight from an archery body or bow maker. These sourced figures give a sense of scale.

The Olympic numbers are elite targets, not starting points. Archery 360 advises starting lower and adding weight slowly, about half a turn of a recurve's tiller bolts every two weeks⁹. It also puts the long term health of your shoulders first⁹.