Basic rule of thumb for most recurves is 4" shorter than the AMO bow length, although AMO specs state 3" shorter for both longbows and recurves.

Neither one is accurate every time, due to differences in bow design and shooter preferances--if possible, measure a string that works and order by that length.

I usually leave mine strung indefinately. How you store it will make a difference though--I rest mine on two pegs, with the weight of the bow resting at each end of the riser--not on the limbs.

Chad