"Right now their plan is to get hitched in August."
The "Keeping Up with the Kardashians" star will turn 18 in the same month.
Jenner, 17, and Tyga want to get a fresh start away from all the drama after they are officiated.
"They are making plans to quit LA, for a brand new life away from her family and his baby mamma, Blac Chyna," the source added.
"Kylie is done with the constant criticism and micro-management from her family, especially Kim, and she's dead set on going her own way as soon as possible."