The parameter that is of immense importance besides the correct arrow length is the so-called spine value. This indicates, in brief, the degree of hardness of the arrow. The principle is: the higher the arrow length, the harder the arrow, ergo the higher the spine value.
For the spine value, we recommend our Spine value calculator. To use such a spine value calculator, you have to enter different parameters like bow type, extension length, arrow length, and some more in the corresponding fields. This way you will easily get the right spine. Alternatively, you can of course also get advice. Good archery online shops also offer this service by mail or phone.