Doesn't matter how long your arm is. The arrows have to be cut to the proper draw length the bow is set at. Head over to an archery shop so that they can measure your draw length and set the bow to fit you. At that point they can tell you what length arrows you will need. They can also help you with what spined arrow your bow will require. Hopefully you will buy from them because usually if you order arrows on line, you will still need to take them to an archery shop to be cut down. If they charge for this, factor this into the price of the online arrows when you compare prices to buying locally. If arrows are bought at an archery shop, they should not charge you the extra to cut them and glue in the inserts for you. Good luck. HD.