I like the ergonomic handle on this scale, as it is easy to hold while lifting the luggage off the floor.  I found that on one weight it weighed the luggage about 2 pounds lighter than the airport scale did.  So I think you need to give yourself about a 2 pound leeway,  just to be safe.  My  husband used it for his luggage and it was about 1 pound lighter.  However, it does help you know about what you have before you get to the airport.