Answer by Suzan Cioc for Is the universe finite or infinite?

Nobody knows. But most probable theory says it is infinite.

UPDATE

The general theoretical description of Universe is given by Friedmann–Lemaître–Robertson–Walker metric. This metric allows Universe to be both finite (closed) and infinite (opened). This depends on k parameter. If k<=0 then the Universe is infinite. Current observations show that k is close to zero, which can mean either infinite or very big (much larger than 14 billions of ly which is observable space size).

I treat this as it is most probably infinite.

UPDATE 2

Lambda-CDM model cannot itself answer the question if the Universe is finite or not. This is just a summation of observable data about what Universe is consist of.