There is no official way to see your MMR in LoL. For now you can only guess a certain range by keeping an eye on the LP distribution after ranked games. Some websites offer a service that gives out a general idea for players.

Is MMR hidden LoL?

As we know, in League of Legends, the MMR system is fully hidden, and there is no reliable way to accurately calculate your MMR rating. Knowing your MMR is crucial to understanding how fast you can climb to the highest tiers of competitive play.

What is your MMR in league?

Match Making Rating, also known as MMR, is a number used by League of Legends to represent a players skill level. This LoL MMR determines which opponents and players you play against.