Inaccurate Measurements on Storage Bags?

hokiepokiemom

Has anyone else run into this issue?  I have the Medela pump and save bags and the Lansinoh bags and both seem to have the same problem - the ounces shown on the pumped bottle don't match the ounces on the bag!

Usually the bags make it seem like there is a half ounce to an ounce MORE than what I think I actually pumped.  With the Medela brand, I'm opening them up all the way so they stand as I pour in the pumped milk from the bottle.  The Lansinoh brand doesn't have the stand up feature and it seems a little bit closer to what is in the bottle but still over.

Do you just trust the bottle? I don't want to dump it into a measuring cup and then into the bag and risk loosing some in all of the transfers. Any suggestions?