Some disagreement exists about what exactly constitutes the length of a knife; whether it is only the blade or if the measurement includes the blade and the handle. If you are concerned about the measurement of your kitchen knives for legal or shipping purposes, call the police department in your area. As the American Knife and Tool Institute points out, laws vary not only from state to state, but even within counties. For typical home use, knife size refers to the blade since the same size blade can be connected to many different sized handles.
Lay a measuring tape down on your kitchen counter.
Place the knife next to the measuring tape. Align the knife tip with the end of the tape.
Read the measurement for the blade only or for the entire blade and handle if that's what you require.
Kitchen knives may be packed in checked baggage according to U.S. airline regulations. However, always remember to sheath knives for the safety of baggage inspectors as well as to prevent damage to your clothing and luggage.