Archery Draw Length Calculator
This archery draw length calculator finds your draw length from your wingspan using the AMO (wingspan − 15) ÷ 2 estimate plus the wingspan ÷ 2.5 check — draw length for beginners and experienced archers alike. Then it converts that number into what you actually buy: arrow length, bow size, and draw-weight guidance. If you searched for a “draw length calculator archery” tool before buying your first bow, this is it. Everything runs in your browser; nothing is uploaded.
How to measure draw length for a bow: there are two standard estimates — the AMO formula and the wingspan ÷ 2.5 shortcut. Neither replaces a pro-shop measurement, but both get you close enough to buy the right bow. A note on finger vs release draw length: finger shooters often draw about 1–1½ in shorter than with a release aid (community-reported; verify at a pro shop).
1. Wingspan → draw length
The wingspan draw length formula is (wingspan − 15) ÷ 2, the long-standing AMO-style estimate. This works as a compound bow draw length calculator and a recurve bow draw length calculator — the formula is about your body, not the bow.
For a youth bow draw length chart, the same formula applies — measure the young archer’s wingspan the same way; just expect the result to change as they grow.
Draw length chart by wingspan
Draw length chart by wingspan — computed live from the same two formulas, not copied from anywhere.
| Wingspan | AMO: (WS−15)÷2 | Alt: WS÷2.5 | Nearest ½ in (AMO) |
|---|---|---|---|
| 60 in | 22.5 in | 24.0 in | 22 1/2 in |
| 65 in | 25.0 in | 26.0 in | 25 in |
| 70 in | 27.5 in | 28.0 in | 27 1/2 in |
| 75 in | 30.0 in | 30.0 in | 30 in |
| 80 in | 32.5 in | 32.0 in | 32 1/2 in |
2. Arrow length calculator & spine
Draw length vs arrow length: your arrow must be longer than your draw length. Easton’s rule is a minimum of 1 in of shaft in front of your rest at full draw; beginners do well with 1–2 in.
3. Bow size fit
This draw length brace height guide is simple: recurve 7–9 in, longbow 6–8 in, compound typically 6–8 in — tune within the range for the quietest, most forgiving shot. Longbow draw length guidance: about draw length + 40 in as a starting point (rule of thumb).
Recurve bow size chart
| Draw length | Recurve bow length (guidance) |
|---|---|
| Under 27 in | 62 in or shorter |
| 27–29 in | 62–64 in |
| 30 in and up | 66–68 in |
Compound bow axle to axle chart
Compound bow axle to axle chart — rough guidance, not a hard rule.
| Draw length | Axle-to-axle (rough guidance) |
|---|---|
| Under 27 in | 30–32 in |
| 27–29 in | 32–35 in |
| 30 in and up | 35 in or more |
4. Draw weight estimator
Draw weight per inch of draw length changes by about 2–3 lb on recurve and longbow limbs — a rule of thumb, not precision. Archers often ask how much weight per inch of draw their limbs gain past 28 in; this estimator answers that.
Worked examples
Example 1 — 70 in wingspan
AMO: (70 − 15) ÷ 2 = 27.5 in (nearest ½ in: 27 1/2 in)
Alternative: 70 ÷ 2.5 = 28.0 in — methods differ by 0.5 in.
Example 2 — 28 in draw, recurve
Arrow length: 29–30 in
Bow size: 62–64 in recurve; brace height 7–9 in.
Example 3 — 40 lb @ 28 in recurve, drawn to 30 in
Estimated actual weight: ≈45 lb (rule-of-thumb band 44–46 lb).
On a compound the peak weight would stay at the module setting.
Frequently asked questions
Q1. How do I measure my draw length from my wingspan?
Stand with your back to a wall, arms straight out at shoulder height, and have someone measure fingertip to fingertip in inches. Subtract 15 and divide by 2 — the AMO estimate. Example: a 70 in wingspan gives (70 − 15) ÷ 2 = 27.5 in, which is 27 1/2 in to the nearest half inch. The wingspan ÷ 2.5 check gives 28.0 in, a 0.5 in difference.
Q2. Which is correct: (wingspan − 15) ÷ 2 or wingspan ÷ 2.5?
Both are estimates, not measurements. The (wingspan − 15) ÷ 2 formula is the long-standing AMO-style standard used by pro shops; wingspan divided by 2.5 is a quick alternative. For a 72 in wingspan they give 28.5 in vs 28.8 in — 0.3 in apart, or 28 1/2 in vs 29 in to the nearest half inch. Use the AMO result as your primary number and the other as a sanity check.
Q3. What is the difference between AMO draw length and true draw length?
AMO draw length explained: true draw length is measured from the nock groove to 1 3/4 in in front of the grip pivot point at full draw, and AMO draw length adds that 1 3/4 in back. So true draw length vs AMO is simply a 1.8 in offset — a 26.25 in true draw is a 28 in AMO draw. Bows are rated in AMO draw length, so buy modules and arrows against the AMO number.
Q4. What arrow length do I need?
Add 1–2 in to your draw length. Easton’s rule is a minimum of 1 in of arrow in front of your rest at full draw, and beginners do well with up to 2 in. Example: a 28 in draw length takes 29–30 in arrows. An arrow that is too short is dangerous — one that is a little long is fine.
Q5. What spine arrow do I need?
Spine depends on draw weight and arrow length — the arrow spine chart compound rows in section 2 give a starting band. From Easton’s 2020 target shaft chart: a 32 lb bow shooting 29 in arrows falls in spine code band 675-600. That is a starting band, not a prescription — confirm with Easton’s online shaft selector and your pro shop.
Q6. What size recurve bow do I need for my draw length?
Bowyer guidance: under 27 in of draw length, choose a 62 in bow or shorter; 27–29 in fits 62–64 in; 30 in and up wants 66–68 in. Example: a 28 in draw length fits a 62–64 in recurve. Brace height usually lands at 7–9 in.
Q7. What axle-to-axle length fits my draw length on a compound?
Rough guidance, not a hard rule: under 27 in of draw, look at 30–32 in axle-to-axle; 27–29 in pairs with 32–35 in; 30 in and up suits 35 in or more. Example: a 29.5 in draw length pairs with roughly 32–35 in. Comfort and string angle matter more than any chart.
Q8. How much does draw length change draw weight?
On recurve and longbow limbs, roughly 2–3 lb per inch away from the 28 in rating — a rule of thumb, not precision. A 40 lb bow rated at 28 in draws about 44–46 lb (midpoint 45 lb) at a 30 in draw, and about 34–36 lb at 26 in. On a compound, peak weight is fixed by your module setting; a longer draw changes the power stroke and arrow speed, not the peak weight.
Q9. How can I tell if my draw length is wrong?
Common draw length too long symptoms: at full draw the string sits more than about 1/2 in past the corner of your mouth or lies across the side of your nose instead of touching its tip, and your bow shoulder creeps upward. Too short feels cramped — you lean your head into the string and cannot settle into back tension. Either way, re-measure and have a coach or pro shop confirm.
Q10. Does draw length affect arrow speed?
Yes. A longer power stroke lets the string push the arrow for longer, so the same bow stores and delivers more energy at a longer draw. Once you know your draw length, plug it into our arrow speed calculator to see the effect in feet per second.
Q11. How do I measure draw length without a bow?
Use the wingspan method above — no bow needed. For a physical check, use a light bow and an extra-long arrow: draw to your anchor while a partner marks the shaft at the front of the riser, then measure from the mark to the nock groove and add 1 3/4 in for AMO draw length. Repeat several times for consistency.
Q12. I already know my draw length — is this the right tool?
This tool answers “what is my draw length” — it solves FOR draw length and its consequences (arrow length, bow fit). If you already know your number, use our arrow speed calculator instead: it takes draw length as an input, with draw weight and arrow weight, and outputs arrow speed, kinetic energy and momentum. Opposite direction, same archery setup.
Sources & method
Every number on this page is computed from the formulas below — spot-checked against primary sources before the test vectors were frozen (see SOURCES.md in the tool folder). Interpolations between published rows are labeled as such.
- Wingspan formula (AMO-style): draw length = (wingspan − 15) ÷ 2. Spot-checks: 75 in → 30 in, 69 in → 27 in (archery forum); 71 in → 28 in AMO, ±½ in per inch of wingspan (IL Archery tech note).
- Alternative: draw length = wingspan ÷ 2.5. Spot-check: 67 in → 26.8 in (HuntingNet); chart 60–75 in (60X Custom Strings).
- Arrow length: minimum draw length + 1 in in front of the rest (Easton 2020 Target Shaft Selector); 1–2 in recommended for beginners.
- Recurve size bands: <27 in → 62 in or shorter; 27–29 in → 62–64 in; 30 in+ → 66–68 in (BobLee Bows). The 29–30 in sliver is interpolated into the middle band.
- Draw weight: ±2–3 lb per inch from the 28 in rating on recurve/longbow limbs (rule of thumb, midpoint 2.5 used for the headline number). Not ±10 lb/in — that figure appears in some briefs but primary sources say 2–3.
- Spine bands: Easton 2020 target chart, compound / release aid rows only; nearest published band and column, labeled as coarse guidance.
- AMO vs true draw: AMO draw = true draw + 1 3/4 in (AMO Standards).
Related tool & scope boundary
Scope: this tool answers “what is my draw length?” — it solves for draw length from your wingspan and derives its consequences (arrow length, bow fit, draw-weight guidance).
Already know your draw length? Our arrow speed calculator works in the opposite direction: it takes your known draw length as an input (with draw weight and arrow weight) and outputs arrow speed in fps, kinetic energy and momentum. Different question, different direction — the two tools complement each other instead of competing.
Have your draw length? Our Bow Sight Tape Calculator builds a printable sight tape from your arrow speed, with 20–100 yard marks and an angle-cut adjuster.
Free tool by NRTechStudio