Compound Bow Sizing: Get Draw Length Right First
Compound bow fit starts with one number: your draw length, which is your wingspan divided by 2.5. Get that right, then choose axle-to-axle length by how you'll use the bow, weigh it rigged rather than bare, and let your dominant eye — not your dominant hand — decide left or right.
By the Archery Care Editorial Team
Watch it done
Reputable tutorials that demonstrate this, hand-picked by Archery Care. The walkthroughs are the creators’ own — we just point you to the good ones (and, where they added chapters, straight to the moment that matters).
Draw length decides whether a compound bow fits you. Not the brand. Not the draw weight. Not the speed printed on the limb sticker. A compound locks into a mechanical wall at full draw, so unlike a recurve — where you can sneak a half inch either way — you're stuck with whatever the cam says. Set it an inch wrong and it stays an inch wrong on every shot you ever take.
Flagship compounds like the Mathews ARC 34 and Hoyt Carbon RX-10 advertise IBO speeds of 338 to 357 fps. None of those fps matter if the bow doesn't fit. A $2,149 flagship set wrong will lose, every time, to a $500 package bow set right.
Finding your draw length
Stand with your back against a wall, arms out in a T, palms forward. Have someone measure fingertip to fingertip, then divide by 2.5. A 70-inch wingspan works out to a 28-inch draw. That's the method the Archery Trade Association's coaches teach, and it gets most people within half an inch.
Half an inch still matters, though. Being even one inch off can cause anything from dropped accuracy to injury. At full draw, the string should touch the corner of your mouth and the tip of your nose. Craning your neck forward to reach the string? Too short. String buried past the corner of your mouth with your release hand drifting behind your ear? Too long.
Two more things worth knowing. Manufacturers measure draw length from the nocking point to the deepest part of the grip, plus 1¾ inches — so the number on the spec sheet lines up with the wingspan math. And your draw length sets your arrow length, which sets your arrow spine, so changing it later means buying new arrows too. Run your wingspan through a draw length calculator, then confirm at a pro shop on a draw board before you spend real money.
Axle-to-axle length follows the job
Axle-to-axle (ATA) is the distance between the two cam axles, and it's usually hiding in the product name. Mathews builds the ARC 30 and ARC 34 on the same platform — the number is the ATA in inches. Same convention with the Bowtech Alliance 30, the Prime Divide 33, and the Hoyt Alpha AX-3 33.
Short bows in the 30-to-31-inch range are for hunters. They swing inside a ground blind, clear a treestand rail, and strap to a backcountry pack without snagging. The trade-off is stability — a shorter bow is twitchier to hold on target, and the string angle at full draw gets sharp enough to crowd your peep sight if your draw runs 29 inches or longer.
Longer bows hold steadier. That's physics, not marketing: more length between the axles resists torque, which is why dedicated target compounds stretch well past anything in the hunting aisle. For most bowhunters, 32 to 34 inches is the honest sweet spot. If you're tall, bias long — a 30-inch draw on a 30-inch bow is fighting geometry the whole way down.
Mass weight and the carbon tax
Bare-bow weight gets ignored on spec sheets and felt on every hunt. Whatever the scale says in the shop, add a sight, rest, quiver, and stabilizer before you judge it — a rigged hunting bow carries noticeably more than the bare riser you held at the counter.
Heavier isn't automatically worse. Mass damps vibration and steadies your float on target, which is why target shooters bolt weight on deliberately. It's mountain hunters who pay for every ounce, and they're who carbon-riser bows like the Hoyt Carbon RX-10 and PSE Sicario Carbon FDS exist for. Carbon also stays warmer against a bare hand in a November treestand. Small thing, until it isn't.
Expect to pay for the diet. Flagships in this class run $1,300 to $2,149, with carbon risers sitting toward the top of that range. If you hunt from a stand fifty yards behind your truck, skip the carbon and put the difference into arrows and a better sight.
Right hand or left hand starts with your eyes
Here's the part beginners get backwards: bow handedness follows your dominant eye, not your dominant hand. A right-handed bow is drawn with the right hand and aimed with the right eye — your weaker arm holds, your stronger side pulls and sees.
Test it now. Point your thumb at something across the room with both eyes open, then close one eye at a time. Whichever eye keeps your thumb planted on the object is dominant; the other one makes it jump sideways.
For roughly 74% of people, eye and hand agree and the choice makes itself. The other 26% are cross-dominant, with two ways out: draw with the weaker hand and aim with the dominant eye, or keep the dominant hand and train the weaker eye (an eye patch over the dominant eye during practice does the work). For a new compound shooter, following the dominant eye is usually the cleaner path — an awkward draw feels normal within weeks, while fighting your own eye never really stops.
Decide before you order. A compound can't be converted; the riser, rest, and sight are all side-specific.
Youth and adjustable bows
Kids grow. Sometimes two inches of wingspan in a single season.
A bow with a fixed 26-inch draw fits a 12-year-old briefly, then becomes a wall decoration. Adjustable-cam bows solve this — Bear's Cruzer line is the standard example, and the current Cruzer G4 adjusts from a 14-inch to a 30-inch draw length on a 29-inch axle-to-axle frame. Bear built the Cruzer platform so draw changes take an Allen wrench, not a trip to a shop with a bow press. One bow covers a kid from first season to adult-sized.
The catch is efficiency. Wide-range cams give up performance to the fixed-draw cams on a flagship like the Bear Redeem or Bowtech Alliance 30 — that's the cost of flexibility, and it's worth paying for a growing archer. An adult who's done growing should buy a bow with a rotating module near their actual draw length and have a shop dial it in exactly.
The order of operations
Fit a compound in this sequence and the rest of the spec sheet mostly sorts itself out.
- Measure your wingspan, divide by 2.5, and verify the result at a pro shop on a draw board.
- Run the eye dominance test and commit to a side before you order anything — handedness can't be changed later.
- Pick axle-to-axle by use: 30 to 31 inches for tight hunting setups, 32 to 34 for all-around work, longer for target lines.
- Judge weight with accessories mounted, and only pay carbon prices if you carry your bow farther than you drive it.
- Buying for someone still growing? Get an adjustable like the Cruzer G4 and re-measure their draw every season.
- Stuck between models? The Find My Bow quiz turns your draw length and use case into a shortlist.
Real questions archers ask about compound bow size
Mined from public archery communities (June 2026); answered by Archery Care using our scored data. Source links go to the original discussions.
How do I know if my draw length is too long without a coach watching me?
Watch for a handful of tells you can catch yourself. If the string slaps your forearm every shot no matter how you rotate your elbow, you're likely overdrawn. Same if your head tilts back to reach the string, the string sits behind the tip of your nose instead of touching it, or you feel your bow shoulder creeping up toward your ear. Film yourself from the side at full draw: your bow arm and drawing forearm should form roughly a straight line through the arrow, not a hyper-extended bow elbow. The classic forum line holds up here: when in doubt, go a half inch short rather than long. A touch short still anchors and holds; too long wrecks your form.
How accurate is the wingspan-divided-by-2.5 formula, really?
Treat it as a starting line, not a finish line. The formula assumes you're "anthropometrically average" — wingspan proportional to height — and it measures fingertip to fingertip, so long fingers inflate your number and short fingers shrink it. Two people with identical arm spans can land an inch apart once you factor in grip, shoulder set, how much your bow elbow bends, and your release. A more honest reading comes from drawing a marked measuring arrow on a light-poundage bow while someone who knows what a clean anchor looks like reads the number. Expect to tweak from there based on how the bow holds and where it floats. The math gets you in the parking lot; your form finds the door.
If I shorten my draw length, do I have to re-set my peep and sight?
Yes, plan on it. Change draw length and your peep almost always needs to move. Lengthen the draw and the peep sits lower relative to your eye, so you slide it up the string away from the D-loop; shorten the draw and it ends up high, which tempts you to tilt the bow and shoot high. How much it shifts depends on axle-to-axle length — a short ATA bow has a steeper string angle at full draw, so the peep moves more for the same change. Your anchor and sight picture move too. Bottom line: any draw-length tweak is a re-tune, not a quick twist. Reset the peep, re-check anchor, and re-zero your pins before you trust the groups.
Does switching from a wrist-strap release to a thumb or hinge change my draw length?
It can, and it catches a lot of people. Release styles have different neck lengths — the distance from where it grabs the D-loop to where it sits in your hand. A thumb or hinge release is usually shorter than a wrist strap, which pushes your release hand farther forward on your face and effectively shortens your reach to anchor. Folks commonly report needing to add a quarter to half inch of draw, or lengthen the D-loop, to keep the same anchor and peep alignment after switching. So pick your release style before you lock in draw length, not after. If you change later, expect to re-set draw or D-loop and re-check your peep height.
A bow says it adjusts 26-31". Will it shoot well at my short draw, or is it a compromise?
Wide-range bows are convenient, but the edges of that range are where efficiency leaks. A single cam or rotating mod that covers a 5- to 6-inch spread is usually optimized somewhere in the middle, so a short-draw shooter near the bottom of the range often gives up speed and a crisp wall. Rough rule from the speed talk: you lose around 10 fps of IBO for every inch under the bow's top draw. If you draw short, you're better off with a bow that uses draw-specific cams or modules, or a model genuinely tuned for shorter draws, rather than one cranked to its minimum. Check how the specific cam system adjusts before buying — some need a press, some swap a cam, some just rotate a mod.
Community Pulse
What owners and shoppers actually say, quantified across 6 public discussions reviewed in June 2026.
When you're unsure, err short rather than long
praiseThe dominant view across the draw-length threads is blunt: if you're between sizes, go shorter. A slightly short draw still anchors, holds steady, and floats well; a long draw wrecks form, slaps your arm, and pushes your head out of position. The dissent isn't really opposition — it's the reminder that too short costs measurable speed and a mushy wall, so don't overshoot the advice and end up cramped.
Formulas and charts are a starting point, not an answer
mixedHalf the room defends wingspan/2.5 and height charts as a fine first guess for someone with no gear; the other half points out they ignore grip, finger length, shoulder set, and release neck, so two same-height shooters can land an inch apart. The practical middle ground that keeps surfacing: use the formula to pick a starting cam setting, then draw a measuring arrow and let an experienced eye and your own hold dial it in.
Short axle-to-axle for the field vs. long for forgiveness
mixedHunters argue a short ATA is easier to pack, swing in a treestand, and shoot in a blind, and that flat-shooting speed bows forgive yardage guesses. Target-leaning shooters counter that nobody shoots a short bow at the Vegas line for a reason — longer ATA holds steadier and forgives form errors at distance. Most land on matching ATA to the job rather than chasing one ideal number, with shot distances and hunting style deciding it.
How we counted: we read 6 public discussions across archery forums and communities, grouped recurring topics, and counted distinct threads (not comments) where each theme appeared favorably or critically. Summaries are paraphrased in our own words; every count links to its sources. Note: Discussion concentrates on ArcheryTalk's draw-length subforum (the "It's EVERYTHING" and wingspan-accuracy threads are perennial) and Rokslide for the ATA and cam-adjustability angles hunters care about. Strong recurring debate: err short vs. long, and how much to trust the wingspan/2.5 formula.