What are the dimensions of the Ryan Air baggage sizer at Berlin Airport?

We know they changed the sizers because the New Bag Policy From November Will Cut Check Bag Fees & Reduce Boarding Delays details the small item was greatly increased and now the sizer is 42 x 30 x 20cm. But the sizer for the primary bag is not mentioned anywhere. With that said, once you paid for priority, they are not so hot on measuring your luggage. They are very much out to measure those who didn't pay, their business is in auxilliary fees and once you paid yours, you are good to go.

The German site (not for a specfic Airport) only meantions your given size for the Priority offer.

Priority und 2 Handgepäckstücke

Fluggäste, die Priority und 2 Handgepäckstücke oder ein Plus-/Flexi-/Family-Ticket oder ein Flugticket für einen Anschlussflug erworben haben, dürfen ein kleines Handgepäckstück mit an Bord nehmen, das unter den Vordersitz passen muss (40 cm x 20 cm x 25 cm).

Priority-Kunden können ebenfalls ein zusätzliches 10 kg-Gepäckstück mit an Bord nehmen, das in den Gepäck-Checker passen muss (nicht mehr als 10 kg schwer und nicht größer als 55 cm x 40 cm x 20 cm) und im Gepäckfach verstaut wird.

This states that it must fit in the luggage checker.

Most articles state that RyanAir is very strict about this, so you should assume that the Luggage-Checker has been changed since 2018 when these new regulations were changed.

If you have practical experience that your piece of luggage fits in the luggage holder on board without any problems, you may be lucky that the difference will be ignored. But you should never assume this will always be the case.

It seems that this is somewhat of a duplicate question, already posted on travel stack exchange here. Your question is dated July 2018, but the current answer must take in account the cabin bag policy updated in November 2018. Your question does not specify what type of bags (cabin or check in?) but let's assume it's a cabin bag since you're asking about "sizers"...

According to Ryan Air's current cabin bag policy, you are only allowed one small personal bag, free of charge, that must fit under the seat in front of you. It states that it must be maximum size of 40 cm X 20 cm X 25 cm. They even have an image showing the dimensions, like so...

Are those sizers at the airport in Berlin still 58cm or have they changed in the last 4 years? I’d rather not go buy a new bag for this trip.

They have changed to 40 cm x 20 cm x 25 cm. It seems you would need a new bag.