LEGAL INFORMATION
Knife Laws
Legal information overview
This section provides general, non-binding information about knife laws in selected jurisdictions. It reflects common statutory rules and widely observed enforcement practices but does not constitute legal advice. Knife legislation and its interpretation may change over time and can vary by location and circumstance. Always consult local laws before carrying a knife.
United Kingdom (England / Wales / Scotland)
Legal framework
UK knife law is primarily governed by the Criminal Justice Act 1988, the Prevention of Crime Act 1953, and the Offensive Weapons Act 2019. Carrying knives in public without lawful authority or a good reason is generally prohibited.
Exception for folding pocket knives
A folding knife may be carried in public without a stated reason if all of the following apply:
• the blade length does not exceed 3 inches (7.62 cm)
• the knife has no mechanical locking mechanism
• the blade folds freely into the handle
Real-world enforcement practice
In practice, a non-locking folding knife with a blade length not exceeding 3 inches is commonly treated as falling under the pocket knife exception and usually does not attract police attention.
Locking folding knives, even with short blades, may be treated as prohibited, as the statutory exception does not apply to locking mechanisms.
Police officers retain discretion under stop-and-search powers based on reasonable suspicion. Case law and legal commentary indicate that there is no single universally binding definition of how blade length must be measured in every situation. Measurement may be determined by police or courts based on their judgment. Relying on partial measurements, such as the cutting edge only, therefore always involves legal uncertainty.
United States of America
Knife laws in the USA vary significantly by state, county, and city. The information below reflects common statutory rules and widely reported enforcement practices.
California
State law does not set a fixed blade-length limit for folding knives. However, concealed carry of knives that may qualify as a “dirk or dagger” can be problematic. Blade shape and interpretation often matter more than exact measurements.
Several cities and municipalities apply practical limits, commonly around 3 inches. Local user experience suggests that non-locking, two-hand-opening knives with blades of 3 inches or less are least likely to cause issues.
Connecticut
State law restricts concealed carry of knives with blades longer than 1.5 inches without a specific lawful purpose. Enforcement tends to be literal. Connecticut is widely regarded as one of the more restrictive states in practice.
Delaware
The current statutory limit is 3.75 inches, previously 3 inches. Restrictions are especially relevant to concealed carry. Many users continue to treat 3 inches as a conservative and safer everyday carry threshold.
Florida
Pocket knives with blades of 4 inches or less are generally permitted. Blades longer than 4 inches require a concealed weapons license. Despite the formal limit, many users prefer blades around 3.5 inches or shorter for routine carry.
Hawaii
Knives with blades longer than 3 inches are restricted. Enforcement is stricter in Honolulu. Local practice favors non-locking folding knives with blades of 3 inches or less.
Illinois
Concealed carry of knives with blades over 3 inches is limited, with narrow exceptions. Chicago historically applies stricter enforcement. Practical advice commonly favors blades of 3 inches or less.
Massachusetts
No explicit blade-length limit exists in statute, but enforcement practice generally treats 2.5–3 inches as the practical maximum for pocket knives, particularly in larger cities.
Michigan
Knives with blades longer than 3 inches may fall under carry restrictions. Urban areas such as Detroit tend to apply lower tolerance thresholds. Users commonly recommend blades of 3 inches or less.
Minnesota
Restrictions may apply to carrying knives with blades longer than 3 inches, depending on context. Minneapolis enforces stricter standards. Practical advice favors non-locking knives under 3 inches.
New Jersey
No formal blade-length limit exists, but enforcement practice is widely regarded as strict. Small non-locking folding knives around 3 inches are generally considered the safest option.
New York
While historical references cite a 4-inch limit, real-world enforcement—especially in New York City—is stricter. Blades of 3 inches or less are widely treated as the practical maximum.
North Carolina
Concealed carry of knives with blades longer than 3 inches may be problematic. Some municipalities apply additional restrictions. Users favor non-locking knives at or below 3 inches.
Rhode Island
Restrictions apply to knives with blades longer than 3 inches in public places. Municipal variation is limited. Classic slipjoint knives under 3 inches are commonly advised.
Washington
Concealed carry of knives with blades longer than 3 inches is restricted. Seattle and Tacoma apply stricter standards. Two-hand-opening knives under 3 inches are generally recommended.
Wisconsin
Although statutory limits have changed, enforcement practice in many areas still references the former 3-inch threshold. Local advice favors non-locking knives under 3 inches.
Denmark
Carrying knives in public is generally prohibited unless there is a legitimate purpose, such as work, hunting, fishing, or another justified activity.
Folding knives without a locking mechanism and with a blade length of up to 7 cm (approximately 2.76 inches) are commonly exempt from the general prohibition.
Blades longer than 12 cm (approximately 4.72 inches) typically require a clearly documented legitimate purpose.