I purchased boxes for shipping Christmas gifts from the UPS store. The sizes on their boxes were 18 x 18 x 18 & 20 x 20 x 20. When I went back to ship them, they charged me postage for 19 x 19 x 19 & 21 x 21 x 21. This was a difference of $11.72!!! They said that the dimensions were inside!! They have to round up to the next inch if it is over the size! They are ripping consumers off!! I contacted UPS and they said this is not correct, but that I have to deal with the UPS Store! Watch Our!! I called other stores and they do not do this! It is a scam and should not be allowed to happen to consumers!! I will shop elsewhere!