Basically guestimate. If the shipping distance isn't far, like a state just south of me, Ohio, Indiana, Ilinois, New York, shipping is generally less, about 6 to 7 dollars. The farther south and west you go shipping is usually more so I charge $8. I generally charge $1 extra per 2 to 3 fan clump extra added to the box. If the order is extremely large I will generally use the flat rate boxes. I know last year I underestimated a package to Texas and I ended up loosing on postage so I am trying to be a bit more careful. I try not to charge any more than a dollar over the actual cost but it is really difficult to do sometimes. If flat rate charges were not so expensive I would just use those but it is costly if the package isn't going very far.
