size up

to size up (third-person singular simple present sizes up, present participle sizing up, simple past and past participle sized up)

1. (idiomatic) To evaluate; to estimate or anticipate the magnitude, difficulty, or strength of something.

   It's a good idea for boxers to size up their opponents before their matches.

   Before we can begin to size up the problem, we'll need more information.

   • 2017 July 16, Brandon Nowalk, “Chickens and dragons come home to roost on Game Of Thrones (newbies)”, in The Onion AV Club‎:

     She approaches like she’s sizing them up. Five boys. Unarmed. A pile of swords over there. Ed Sheeran is there, but that’s not even the surprise.

   • The Century

     We had to size up our fellow legislators.

2. To wear a larger size of clothing.

   This shirt runs tight, so you should size up.

• upsize