Archery term
Grains
What does Grains mean?
Grains are units of mass used for arrow points and complete arrow weights. One grain equals exactly 64.79891 milligrams, or about 0.0648 grams. The unit is abbreviated “gr” in archery specifications; it does not mean grams. Check the bow or crossbow maker’s minimum finished-arrow mass.
Primary source for this term: NIST Handbook 44, Appendix C: Units of Mass (2026)
Why it matters
A grain scale lets you compare arrow components and calculate total arrow weight in the same unit used by most shaft and bow charts. For a quick conversion, 100 grains is about 6.48 grams. Do not confuse a 100-grain point with a 100-gram point: the latter would be more than fifteen times heavier.
What to check
- Convert first: 1 gram is about 15.432 grains, and 1 grain is about 0.0648 grams.
- Add point, insert, nock, and fletching to shaft mass to estimate the finished arrow.
- Follow the bow or crossbow maker’s minimum finished-arrow mass.