Archery Draw Length Calculator
Draw length from wingspan for starters.
What it does
Draw length sets every archery choice after. Arrows cut to it, bows fit around it, and anchors repeat from it. Wingspan divided by two and a half lands the starting number in seconds.
The tool above divides either unit. With seventy inches the draw is 28 inches with 71.1 centimeters beside. With 170 centimeters it is 68 centimeters with 26.8 inches. A 65 inch span gives 26 inches. Shops round to stocked sizes from there.
Form finishes the fit. Anchor under the chin, level shoulders, and the release all move the tape an inch, so coaches confirm at full draw rather than trusting arms alone. Youth archers outgrow settings yearly.
This page estimates starting length only. It does not set draw weight, arrow spine, or safety rules. Ranges fit the archer before selling the bow.
How to use
- Pick imperial (in) or metric (cm).
- Measure wingspan fingertip to fingertip.
- Read draw length first.
- Read the converted draw beside.
- Round to stocked bow sizes.
- Confirm at full draw with a coach.
Formula
- wingspan
- Fingertip to fingertip wingspan.
- draw
- Nock to grip throat at full draw.
- 2.5
- 2.5 divisor of the wingspan rule.
Wingspan estimate for starting length. At very short or long spans stock bows step in inches, so round with the shop. Anchor and release style sit outside this line.
Worked example
Example: 70 in wingspan
Defaults: imperial 70 in fingertip to fingertip. Metric mirror converts inside.
- Inputs (imperial default): 70 in wingspan.
- Draw: 70 / 2.5 is 28 in draw.
- Metric: 28 times 2.54 is 71.1 cm draw.
- A 170 cm wingspan gives 68 cm draw.
- Confirm at full draw with a coach. Tool shows the same.
Reference table
| Wingspan | Draw | Converted |
|---|---|---|
| 70 in | 28 in draw | 71.1 cm draw |
| 170 cm | 68 cm draw | 26.8 in draw |
| 65 in | 26 in draw | 66 cm draw |
| 178 cm | 71.2 cm draw | 28 in draw |
| 60 in | 24 in draw | 61 cm draw |
Limits
- Estimate only. Form shifts inches.
- Starting point. Shops confirm.
- No weight or spine model.
- Youth growth excluded.
Common mistakes
- Measuring with bent elbows.
- Using shoe height as wingspan.
- Rounding before dividing.
- Buying arrows to estimate, not draw.
- Skipping coach confirmation.
Try it yourself
Quick checks. Answers sit tucked under each question.
170 cm wingspan?
Draw is 170 / 2.5 is 68 cm with 26.8 in beside.
65 in wingspan?
Draw is 65 / 2.5 is 26 in with 66 cm beside.
Questions
How is draw length figured?
Wingspan / 2.5. Here 28 in draw.
How do I measure wingspan?
Arms outstretched fingertip to fingertip, level, measured straight.
Is wingspan the final word?
Yes. Anchor, release, and bow style shift the final inch.
How long should arrows be?
Shops cut arrows about an inch past the rest at full draw.
Does this fit kids?
No. Youth and adaptive archers need fitted coaching.
Does this set poundage?
No. Draw weight needs separate fitting and progression.