USPS Calculation Question

I have the following options selected for types of mailings
Priority Mail Small Flat Rate Box
Priority Mail Medium Flat Rate Box
Priority Mail Large Flat Rate Box

Problem is if I have lets say 120 items to ship which will not fit in a Small or Medium box it still shows a value for all three sizes

example

USPS Priority Mail® Large Flat Rate Box ($14.95)
USPS Priority Mail® Medium Flat Rate Box ($10.95)
USPS Priority Mail® Small Flat Rate Box ($5.20)

How do I ensure that if the items will fit than the option does not show up.

I am having the same issue.  I went in and added the weights, widths, lengths, and heights for all products; however, my customers still get the option to ship giant orders, or large products in flat rate envelopes.  Any guidance is much appreciated!!

See my last reply to this post.

nopTools Shipping Director can handle this, but you would need to come up with some criteria to determine which options to exclude - e.g. Total Weight,  Total Volume, Category products are in, etc.