Bow Draw Weight Calculator

Poundage, Not Length — A Concept-Orthogonal Calculator

The Bow Draw Length Calculator on this site answers "how far should I pull the string back" — a linear measurement of your wingspan. This page answers an entirely different question: "how hard should that string be to pull" — a force measurement in pounds. The two numbers are concept-orthogonal: a 28″ draw archer can ethically shoot anywhere from 25 lb (target, beginner) to 70 lb (elk, advanced), and the right poundage depends on age, build, experience, and the game you intend to harvest — not on your draw length.

Most generic "draw weight chart" pages hand you a single static lookup table indexed by body weight or age. That approach ignores the ethical floor for the species you intend to hunt — a 50 lb compound is plenty for whitetail but is a one-star-out-of-five ethics rating for elk. This calculator treats poundage selection as a multi-parameter config problem: the age band sets a baseline, gender and experience shift it, and the target species enforces a hard minimum that no other parameter can override. The terminal UI above rebuilds the recommendation live every time you change a parameter, and the config text is copy-pasteable into a build sheet.

Draw-Weight Config Parameter Matrix

Every parameter that governs a safe and ethical draw-weight selection, with the live value plugged in for the current selection. Risk levels: high = voids warranty or wounds game, medium = degrades accuracy or speed, low = tuning preference.

Performance, Warning, and Production-Don't Cards

Hunting Species Minimum Draw Weight

Each game species carries an ethical and (in most jurisdictions) legal minimum draw weight. The numbers below combine state DNR regulations with field-ethical floors from broadhead penetration testing — a 40 lb bow that meets the legal minimum is still marginal in the field if your arrow weight drops KE below 40 ft-lbs. Always pair poundage with the Arrow Kinetic Energy Calculator to verify the build carries enough energy for clean penetration.

IBO Draw Weight Standard Explained

The IBO (International Bowhunting Organization) draw weight standard is 70 lb peak, measured at full draw on a compound bow set to the IBO speed specification: 70 lb peak weight, 30″ draw length, 350 grain arrow, zero string accessories. The IBO 70 lb reference is the same number used in the IBO speed formula — it is the universal baseline against which manufacturer speed ratings are computed, so any bow rated "340 fps IBO" assumes a 70 lb peak draw weight at the chronograph.

IBO peak weight is not the holding weight. With an 80% let-off cam, a 70 lb IBO compound holds only 14 lb at full draw — which is why a 70 lb hunting compound is comfortable for a moderately fit adult, while a 70 lb recurve (no let-off, held at peak) is elite territory. The IBO standard also specifies that the 5-grains-per-pound arrow mass floor (350 grains at 70 lb) must be respected; going below it during chronograph testing risks limb damage and voids the manufacturer warranty.

Recurve bows do not use the IBO standard — they use the AMO standard, which measures peak weight by hanging the bow from a calibrated force gauge and drawing the string 2″ past the back of the riser at 28″ draw. A 50 lb AMO recurve and a 50 lb IBO compound are not directly comparable: the recurve is held at 50 lb at full draw, while the compound is held at 10 lb (after 80% let-off) and only briefly spikes to 50 lb at the cam's peak just before the valley.

Recurve vs Compound Draw Weight Measurement

The two bow types are measured with different tools, on different fixtures, at different points in the draw cycle. Mixing the two — or applying a recurve measurement protocol to a compound bow — produces wrong numbers that propagate through your spine and KE calculations.

Scaling From One Bow to a Family Setup

When a single archer's bow selection scales from a personal hunting bow to a household family setup — say a parent plus two youth archers — the poundage selection problem changes shape. The compound's wide-range draw-weight module (10–15 lb turn-dial range per limb) lets a single bow cover 40–60 lb across three users, but the arrow selection cannot be shared: each user needs spine-matched arrows because dynamic spine is sensitive to draw weight. A 400-spine arrow correct at 60 lb is dangerously weak at 70 lb and over-stiff at 50 lb.

The recommended evolution: start with a single adjustable compound for the parent (set 55–60 lb), buy each youth a dedicated ILF recurve with swap-in limbs (10–20 lb for the younger, 25–35 lb for the older), and never share arrows across users. Run this calculator for each family member separately — the age, gender, and experience shifts compound across users, and a single household can land anywhere from 15 lb (youngest youth) to 70 lb (advanced adult) on the same weekend range trip.

Bow Draw Weight FAQ

Poundage Is a Force, Not a Length

Picking the right draw weight is a force-selection problem, not a length-selection problem. Use this calculator as the first step of any bow purchase or hunt-prep cycle: get your age/gender/experience/game-configured recommendation, verify it clears the species ethical floor, then take that poundage into the Arrow Spine Chart to match shafts, and into the Arrow Kinetic Energy Calculator to verify the build carries enough energy at the target. The three tools chain: poundage → spine → energy.

For the underlying draw-length math (which is orthogonal — wingspan-based, not force-based), open the Bow Draw Length Calculator. For the broader archery calculation walkthroughs, the Archery Guides hub covers speed, FOC, weight, and trajectory from first principles.