One of THR's members has a book and webpage about knife laws in the 50 states and most major cities. I haven't looked at it thoroughly, but at first glance it seems very promising and more authoritative than the effort on this page.

If nothing else, this page should make it very clear that state-level knife-carry laws are a disaster, making it difficult for anyone to know in advance just how their knife of choice will be viewed by prosecutors or law enforcement in any particular jurisdiction.

This is only a summary, and glosses over various particulars that may be important to you. This is not legal advice. Some of this information could be flat-out wrong. If there are case cites for a State, chances are that the other information for that state is fairly accurate.

Bernard Levine's site has collected statutes for all the States, but the occasional caselaw quotes lack citations.

Carl Donath has a state knife law summary similar to this one, and perhaps less confusing.

Send corrections, updates, and case cites to tyme on via PM, or webmaster at this domain -- and please don't forget to mention which State your information relates to.

Local Ordinances (only scattered cities are included)

Brief summary of [Practical] Blade Length limits for Knife Carry in the U.S.

Yes = seems to be legal; No = seems to be illegal

State open / cncl -folder- -fixed- dagger auto bali univ notes
FED both 2" s no no no no n/a
AL (BL) cncl yes <"long"* <"long"* yes yes 13A-11-50; * caselaw calls long single-edged knives bowie knives, which are banned for concealed carry; see Smelley v State 472 So.2d 715 (1985). Butcher knives are bowies via Brewer v State 113 Ala. 106 (1897); see also Haynes v State 6 S.W.2d 319.
open yes yes yes yes yes
AK (BL) cncl yes* no no no no 11.61.200-240; * statute bans switchblades and gravity knives completely, and it bans concealed carry of anything but an "ordinary pocketknife". Balisongs are not gravity knives: State v. Strange.
open yes yes yes no yes
AZ (BL) cncl yes*? no no no ?* 13-3102; * "pocket knife" only; no useful caselaw. Statute is constitutional: Dano v Collins 802 P.2d 1021 (1990).
open yes yes yes yes yes
AR (BL) cncl 3.5" s 3.5" s 3.5" s 3.5" s 3.5" s 5-73-120,121; travelling exception; sec. 120 bans carry of anything with intent to use as a weapon. A three-justice dissent in Garcia v State 969 S.W.2d 591 (1998) makes a good argument against the constitutionality of the 3.5" limit, with a good U.S. Supreme Court quote toward the end of the dissent. Sec. 120 was enacted after 121, and they overlap; 121 probably should have been repealed, and 121 is probably unconstitutional. Also, Nesdahl v State 890 S.W.2d 596 (1995) and Smith v State 411 S.W.2d 510 (1967).
open 3.5" s 3.5" s 3.5" s 3.5" s 3.5" s
CA (BL) cncl yes no no no no* see 626.10 12020(a), 653k;See Jim March's Excellent CA knife law summary and the CA county ordinances in the "local ordinances" link just above this table. For instance, L.A. bans open carry of 3"+ knives (with vague "lawful recreation" exception); Oakland bans 3"+ knives completely. A much despised case, People ex rel. Mautner v Quattrone 211 Cal.App.3d 1389 (1989), held that butterfly knives are covered by CA's switchblade prohibition. People v Rosalio S. 41 Cal Rptr.2d 534 deals with a leatherman and the 2.5" school limit, finding that a sharpened edge of less than 2.5" did not violate the law. In Re: T.B. G039990 (2009) found that a multitool with a 1" blade, presumably a keychain-type miniature model, violated 626.10(a) prohibiting locking folders in K-12 schools since said multitool comprises a folding knife which locks into place. In Re: Angel R, G039120 (2008) concludes that a knife which can be opened by a flick of the wrist (possibly because the detent mechanism was worn out) is a switchblade.
open yes yes no no no*
CO (BL) cncl 3.5" s 3.5" s 3.5" s no no 18-12-101..105; open carry of anything may be legal, but expect to be hassled particularly in Denver. There is a hunting/fishing exception. Knives <3.5" are illegal to carry concealed with intent to use as a weapon, but otherwise are okay: A.P.E. v People 20 P.3d 1179 (2001). The knife in that case is not described, but presumably it is a balisong that was ruled to be a gravity knife at trial, mentioned in People v Pickett, 571 P.2d 1078 (1977). People v Gross 830 P.2d 933 (1992) is sometimes cited in reference to CO knife laws, but it's really a stretch to connect that to typical enforcement of sec. 102.
open yes yes yes no no
CT (BL) cncl 3.4"* cl / 4" s ? 1.5" s 1.5" s no 53-206; * vague caselaw. Highly dubious. <3" or a non-tactical folder is safer. 3.5" knife used in self defense may be prosecutable: State v Holloway, 528 A.2d 1176 (1987), despite State v Harris 258 A.2d 319 (1968) which held that without obvious intent, the 4" limit was strict and could not be lowered by a finding that the knife was a dangerous weapon. CT is truly a land of sheep: in State v Sealy 546 A.2d 271 (1988), a knife with a 4.5" blade is described as a butcher knife.
open 3.4"* cl / 4" s ? 1.5" s 1.5" s no
DE (BL) cncl 3" s no no no no 11.222,11.1442,11.1446; 1446 bans switchblades (anything using a spring or gravity)
open yes yes yes no no?
D.C. (BL) cncl 3" s 3" s 3" s no 3" s 22-4514,22-3204; 4.5" folder is illegal: Scott v. United States, 243 A.2d 54 (1968). Technically, by law knives with blades longer than three inches are illegal only with intent to use unlawfully, but as in many states, the burden of proof is typically reversed when dealing with larger knives.
open 3" s 3" s 3" s no 3" s
FL (BL) cncl 4"* cl no no no no 790.001,01; * It seems dangerous to rely on this. L.B. v State 700 So.2d 370 (1997) suggests that a closed folder of 3.75" is okay, due in part to an identical AG opinion from 1951 (stating knives up to 4" are common pocketknives). However, that "common pocketknife" exception is only for the definition of "weapon". "Concealed weapon" in 790.001 has no "common pocketknife" exception as the "weapon" statute does; this distinction is presented in Baldwin v State, 857 So. 2d 249 (2003). State v. Ortiz, 504 So. 2d 39: a 4" folder may be a concealed weapon because determination of "common pocketknife" is a jury question. Folding knives must be carried closed: Walls v State 730 So. 2d 294 (1999), Porter v State 798 So.2d 855 (2001). A tactical knife may not be a "common pocketknife": J.D.L.R. v State 701 So. 2d 626 (1997). There is plenty of other interesting caselaw: 504 So. 2d 39 (1987); Nystrom 777 So. 2d 1013; State v. A.D.H., 429 So. 2d 1316 (1983); Simmons v. State, 780 So. 2d 263 (2001); Garcia v State, 789 So. 2d 1059 (2001). For legal status of icepicks and razors, see State v. Tremblay, 642 So. 2d 64 (1994) and Robinson v. State, 547 So. 2d 321 (1989)
open yes yes yes yes yes
GA (BL) cncl ? no no no ? 16-11-126,127,127.1; The statutes prohibit carrying any offensive/defensive weapon concealed. It is also illegal to carry any such knife to a public gathering. In short, don't ever claim self defense as a reason for carrying a concealed knife. Carry laws at schools or at school events are much more strict (no dirks, bowies, switchblades, or knives with blades over 2"). Violation of those school restrictions (127.1) is a felony.
open yes yes yes yes yes
HI (BL) cncl yes* yes* no no no 134-51,52,53; Those sections ban dirk/dagger/deadly weapons, switchblades (spring/gravity), and balisong/butterfly knives, respectively. * must not be principally designed as a weapon.
open yes yes yes no no
ID (BL) cncl no 18-3302; Dirks and bowie knives are illegal except in the wilderness. So are "other deadly or dangerous weapon[s]", whatever that's supposed to mean.
open no
IA (BL) cncl 5" s 5" s no no no 702.7 (def.), 724.4; Balisongs are "dangerous weapons" and are illegal to carry concealed: In Re. F.A.B. (2004). It's likely that daggers and autos would also be "dangerous weapons". (Note: entry fixed 2004-03-13)
open yes yes yes yes yes
IL (BL) cncl yes yes yes no According to statute, a crime involving most knife carry only occurs if there is intent to use the knife unlawfully. Like several other state, though, in liberal areas like Chicago it's likely that unlawful intent would be presumed.
open yes yes yes no
IN (BL) cncl yes yes yes no yes IC 35-47-5-2
open yes yes yes no yes
KS (BL) cncl 4" s no no no no
open 4" s no no no no
KY (BL) cncl SAK?* cl no no no no 500.080, 527.020; * Stout v Commonwealth 33 S.W.3d 531 (2000) held that a 3" locking folder is deadly weapon. Also see Mason v Commonwealth 396 S.W.2d 797 (1965), Montgomery v Commonwealth 346 S.W.2d 479 (1961), Williams v Commonwealth 304 Ky. 359 / 200 S.W.2d 926
open yes yes yes yes yes no
LA (BL) cncl <4"* cl no no no * State v. Ordon suggests that a 4" knife is illegal;
open yes? yes yes no
ME (BL) cncl yes yes yes no yes
open yes yes yes no yes
MA (BL) cncl yes yes no 1.5"? s yes 269-10(b)... a typical lawyer-turned-legislator-crafted 232-word sentence fragment. I have no idea what it means, and I haven't found any illuminating caselaw.
open yes yes no 1.5"? s yes
MD (BL) cncl yes ?* no no no GCR 4-101; * technically "yes" unless it's intended as a weapon, but probably no. Again, this is a situation where intent is required by the statute, but ends up being presumed unless the defendent can prove otherwise. Anderson v State broadly discusses the statute and some D.C. caselaw on the subject.
open yes yes yes yes yes
MI (BL) cncl yes yes no no yes 750.226a; 750.227; It's illegal to carry anything above a 3" statutory limit with intent to use unlawfully. The standard caution applies: unlawful intent could be presumed by a court if the knife is scary enough. Also, no carry of daggers/stilettos, concealed or not, is allowed in a vehicle.
open yes yes yes no yes
MN (BL) cncl yes? yes? ? no yes? 609.66(1)(4) and (5);
open yes? yes? ? no yes?
MO (BL) cncl 4" s no no no ? 571.010(10),571.030;
open 4" s no no no ?
MS (BL) cncl yes* yes* no no yes* 97-37-1; * bowie and butcher knives are illegal to carry. No definitions are given.
open yes yes yes yes yes
MT (BL) cncl 4" s 4" s no no 4" s 45-8-316,331;
open yes yes yes no yes
NC (BL) cncl 3.5"?* cl no? no no no? 14-269; * 4.5" handle length, carried closed, is legal (therefore the blade length is probably around 3.5"): Dale B. (juv) 96 N.C. App. 375. There is very little other caselaw, and like in most places, the statute may not be routinely enforced.
open 3.5"?* cl no? no no no?
ND (BL) cncl 5" 5" no no 5"? 62.1-01;
open yes yes yes yes yes
NE (BL) cncl yes yes* no no? yes 28-1202. * Bowies are prohibited. 28-1201 is disturbing; it defines knives as anything more than 3.5", but "knife" is never used in Section 28 in a manner that could utilize that definition.
open yes yes* no no? yes
NH (BL) cncl yes yes no no yes 159:16;
open yes yes no no yes
NJ (BL) cncl * * no no no 2C:39-3; Apparently you need an explainable lawful purpose to get away with carrying anything besides a dagger/dirk/stiletto, auto, gravity, or balistic knife, which are flat-out illegal. Even then, as in most states, certain less-common knives would probably be "per se" weapons even with an explanation. * NJ state police seem to think all knives are illegal unless the carrier has an explainable lawful purpose. Legally, that probably isn't so, but it may take a court hearing, some lightening of your pockets, and some quality time in jail to sort things out.
open no no
NM (BL) cncl no no 30-7-8;
open yes no
NV (BL) cncl yes yes yes 2" s
open yes yes yes 2" s
NY (BL) cncl yes yes yes no yes* Other than switchblades and gravity knives, dangerous knives are only illegal when coupled with intent to harm another; that intent is presumed if the carrier possesses drugs. In re Alicia P. cites interesting knife-related caselaw. NY law requires malintent for most kinds of knives before carry becomes illegal. People v Kindred 18 A.D.2d 1086 held that a 15-18 inch knife was a "per se" weapon, possibly under a defunct statute. * Balisongs are not gravity knives: People v. Zuniga (2003).
open yes yes yes no yes*
NYC cncl 4" s 4" s 4" s no no? Switchblades are banned on account of State law. Limits are for concealed carry only; open carry is banned.
open no no no no no
OH (BL) cncl 4"* cl no no no 2923.12; concealed deadly weapons are prohibited. Balisongs are deadly weapons: Columbus v. Dawson. * A locking 4" folder is not a deadly weapon by itself, but these cases talk about the knives as if they required two-handed opening; modern knives with thumbholes/studs for one-handed opening may not be legal: State v. Anderson,
open yes yes yes yes yes
OK (BL) cncl yes yes* no* no* no*
open yes yes* no* no* no*
OR (BL) cncl yes yes no no no 166.240; prohibitions may not be constitutional: State v. Delgado, 298 Or. 395 (1984)
open yes yes yes yes? yes
PA (BL) cncl yes yes Balisongs are okay: Commonwealth v. Miles.
open yes yes
RI (BL) cncl 3" s 3" s 3" s 3" s 3" s 11-47-42;
open yes yes yes yes yes
SC (BL) cncl yes yes yes yes yes
open yes yes yes yes yes
SD (BL) cncl yes yes yes yes yes* * 22-14-29: carry by minors is restricted;
open yes yes yes yes yes*
TN (BL) cncl 4" s 4" s 4" s no
open 4" s 4" s 4" s no
TX (BL) cncl 5.5" s 5.5" s no no no 46.02; Note: caselaw suggests that blade length is measured from tip to handle; see McMurrough v State 995 S.W.2d 944; Rainer v State 763 S.W.2d 615. Folding knives can be daggers if dual-edged: see Goldberg v State 95 S.W.3d 345. Balisongs/Butterfly knives are opened by centrifugal force and are prohibited: Smith v. State, 1988 (no cite). Note, however, that that case is not citable as authority for the Prosecution if you are arrested for bali carry. Other cases mentioning in passing that butterfly knives are illegal: 926 S.W.2d 307 (1996); 2003 Tex. App. LEXIS 5473.
open 5.5" s 5.5" s no no no
UT (BL) cncl 3.5"?* cl no no no * This is a guess based on Kirkwood (cite below; 4" bad, 3" good). "Dangerous weapon" cases tend to involve restricted persons, so the law may not be generally enforced on people stopped for ordinary infractions. See State v Kirkwood, 47 P.3d 111 (2002). A very unhappy Appeals Court also decided that a 4.5" folding knife is a "dangerous weapon", 898 P.2d 271 (1995) due to stare decis of State v Archambeau 820 P.2d 920 (1991).
open yes yes yes yes
VA (BL) cncl yes yes no no yes 18.2-308;
open yes yes yes yes yes
VT (BL) cncl yes yes yes 3" yes 13-4003,4013,4016;
open yes yes yes 3" yes
WA (BL) cncl yes yes no no no 9.41.250, 270;
open yes yes yes no no
WV (BL) cncl 3.5" s 3.5" s 3.5" s no no 61-7-2,3; Statute declares that most knives over 3.5" are illegal to carry concealed; pocketknives <3.5" and hunting/fishing knives (which probably require evidence of sporting use) are legal, anything else is in a gray zone.
open yes yes yes yes yes
WI (BL) cncl yes* no no no no 941.23,24: concealed carry of "dangerous weapons" and switchblade/gravity/flickable knives is strictly illegal. Balisongs are illegal: 149 Wis. 2d 534 (1989).
open yes* yes yes no no
WY (BL) cncl ? no no no ? 6-1-104,6-8-104; "deadly weapon" is determined by an item's inherent intended use or by carrier's intended use. Statute is constitutional: State v. McAdams (1986).
open yes yes yes yes yes

Where blade length is specified, "s" means the length limit is written into the statute, while "cl" means the length limit is based on caselaw.

The "college" column indicates a statutory limit for colleges more restrictive than usual. Many colleges have their own policies, and breaking them might result in unpleasant hassling by police, but such policies are not law.

Stilettos/poniards are not dealt with here. (Sharp pointy things with no functional edge.)

CCW exemptions to non-firearm carry laws are not mentioned in this page. If you have a CCW/CHL/CHP, it may give you permission to carry knives that would otherwise be illegal. This is notably the case in Florida, where a handgun permit is really a concealed weapon permit, and allows you to carry virtually anything as long as you keep it concealed.