Free archery calculators
Set up your bow with
real numbers, not guesswork
Arrow spine, front of centre, kinetic energy and draw length, calculated properly and not locked to one manufacturer's shafts. Plus honest gear guidance for archers who would rather understand the setup than be sold one.
Researched from published specifications and verified owner reviews. We do not test gear in person.
Calculators
The math you cannot avoid when setting up a bow.
KE and momentum, with the 5 gr/lb safety check
Cross-manufacturer, not locked to one shaft brand
Wingspan method plus a sanity check
Front of centre with target ranges
Build up grains from components
Real fps from an IBO rating
What you should actually be pulling
True horizontal distance from a treestand
Start here
Why this site exists
Almost every arrow spine and FOC calculator online is run by a shaft manufacturer, and every one of them recommends their own shafts. That is not necessarily wrong, but it is not neutral either. These tools compare across manufacturers, show their formulas, and tell you when the honest answer is that two options are equivalent.
We earn a commission if you buy through our links, at no cost to you. That never changes which product we recommend, and we say plainly when something is not worth the upgrade.