🎯 Draw Weight Calculator
See the real peak weight your recurve or traditional bow pulls at your draw length. Bows are rated at 28"; this adjusts by about 5% of the rated weight per inch above or below.
🎯 Effective draw weight
Recurve and traditional (longbow) draw weights are marked at a 28" draw and change by roughly 5% of the rated weight — about 2–3 lb — for every inch away from 28". Compound bows do not follow this rule: their cams hold a fixed peak weight, adjusted with limb-bolt turns or a module change.
The number on the limbs isn't the whole story
A recurve or longbow marked "40 lb" is 40 lb at exactly 28 inches of draw. Draw it further and the limbs store more energy, so you pull more; draw it shorter and you pull less. The change is close to 5% of the rated weight for every inch — enough that two archers shooting identical limbs can be working against noticeably different weights.
Knowing your effective weight helps you avoid being over-bowed, pick the right arrow spine, and compare bows honestly. Remember this rule is for recurve and traditional bows only — compounds hold a fixed peak weight and are adjusted a different way.
❓ Frequently Asked Questions
Why is my bow's actual draw weight different from the number on the limbs?
Recurve and traditional bow weights are marked at a standard 28-inch draw. If your draw length is longer you pull more than the marked weight; if it's shorter you pull less — by roughly 5% of the rated weight, about 2–3 lb, for every inch away from 28 inches.
How much does draw weight change per inch?
About 5% of the rated weight per inch. That's roughly 2 lb per inch for a 40 lb bow and about 2.5 lb per inch for a 50 lb bow. So a 40 lb bow drawn to 30 inches actually peaks near 44 lb, while the same bow drawn to 26 inches peaks near 36 lb.
Does this work for compound bows?
No. This calculator is for recurve and traditional (longbow) bows. A compound bow's cams hold a fixed peak weight through the draw cycle, so its weight is changed with limb-bolt turns or a different module or cam, not by your draw length.
Why does effective draw weight matter?
It's the weight your body actually works against and the number that drives your arrow-spine choice. Buying limbs by their marked weight without adjusting for your draw length can leave you over- or under-bowed and mis-spined.
How do I find my draw length to use here?
Measure your arm span and divide by 2.5, or use our Draw Length Calculator, then confirm it on a draw-length arrow at a range. Enter that figure here to see the peak weight you'll really pull.