How to Measure a Knife Blade

••• Scott Feldstein

Explore America's Campgrounds

The definition of a legal knife blade can be different from state to state. For instance. the state of Texas said in an unpublished appeal (Perez v. State 1999 WL 521705) that a knife blade includes the sharpened and unsharpened parts of the blade above the knife handle. The American Knife and Tool Institute states that a knife blade should be measured from where the knife handle ends. Follow the steps below and check state laws to find out if your knife may be carried legally.

    Place the knife on a table with the blade out.

    Place the end of the measuring tape or ruler against where the blade meets the knife handle at the lowest intersection.

    Measure blade to its highest point at tip. This is your blade measurement.


    • A Buck knife and a KaBar knife have different handles. Begin your measurement from the lowest possible point on a slanted handle.


    • Knife laws vary from state to state. Possession of a knife, even of legal blade-length, can still be illegal in certain places. For example, it is illegal to carry any knives in Pennsylvania schools. Knives labeled as "combat knives" by the manufacturer may be illegal in your state regardless of blade length.