Litir (ingiriis: Liter ama Litre) waa halbeeg lagu cabiro muga iyo miisaanka walax ama shay meel madhan buuxin kara. Halbeegan astaantiisu waa l. Litir waxaa inta badan lagu cabiraa dhamaan walxaha dareeraha ah. Hal litir waxay la mid tahay 1 desimitir sadex-laaban (cubic decimetre), ama 1,000 sentimitir sadex-laaban (cubic centimeter), ama 1/1,000 mitir sadex-laaban (cubic meter). Sidoo kale, hal litir (ama desimitir sadex-laaban [cubic decimetre]) waxay la mid tahay 10×10×10 sentimitir. Halbeegan litir kama mid ahan Nidaamka Caalamiga ee Halbeega Dunida, laakiin wuxuu xubin ka yahay halbeegyada loo yaqaano Cabirka Guud ee Culeyska iyo Miisaanka (General Conference on Weights and Measures) oo loo soo gaabiyo (CGPM). Maqaalkan waa la bilaabay. Hadii aad wax ka taqaanid fadlan ka caawi Wikipedia in aad Wax ku dartid. Qoraalkaagu ha noqdo mid faa'iido leh oo dhexdhexaad ah.