wardrobe questions

[cbus]

I'm a male applicant invited to an in person interview for an interdisciplinary PhD program.  I will be interviewing with faculty from the following departments: Math, Computer Science and Engineering, Biomedical Engineering.  My day to day wardrobe is flip-flops, sweatpants and a t-shirt/sweater but I fear that this is too casual for a recruitment event where I will be interacting with potential employers.  On the other hand, none of my professors ever complained about what I wore to the lab, class, etc.  I'd prefer to go about this like a normal day at school but I don't want to come off as sloppy.

[TakeruK]

I think you are correct that your day to day is too casual for an interview. Note that not receiving complaints is not the same as having acceptable wardrobe.

I sympathize with your desire to go about this like a normal day at school, but remember that as a graduate student, you are not really "going to school". It's a little more professional and I would think about it as going to work (although perhaps not quite the same work as an office job or an industry job). 

If you are not the type of person that really cares about their wardrobe, here's an easy outfit that I find to be very comfortable and will make acceptably professional for almost all grad school visit/interview situations: polo shirt, khakis, clean sneakers or dress shoes. e.g. https://youlookfab.com/wp-content/uploads/2008/04/level-1.jpg

I would say that the outfit above is the minimum casual-ness you would want to wear. I would call that outfit on the casual end of "business casual" and if the interviewing schools specifies a casual dress code, I would not go any lower than that. 

It is slightly boring but honestly a safe choice. There was one visit where the only two guys (including me) wore pretty much exactly that. You can vary some things at the same casual level (e.g. replace the polo with a button up shirt with a collar) and you can add other things like a belt (especially if you feel one other part of your outfit is a little less professional). You can also go one step higher and wear a dress shirt and dress pants with dress shoes. Adding a tie could bring it up another half step but it depends on what you're wearing. I think a jacket might be too formal, but it's better to be overdressed than underdressed. I'm not saying you have to do all of these things at all, just showing you the gradient.

For your case, you are interviewing in a wide range of departments with potentially a wide range of cultures and dress codes. Biomedical fields tend to be more sharply dressed, when these interviewees are on my campus, they are wearing dress shirts and a sizeable number of them have ties and jackets. You might want to email some people and learn about dress expectations. Since it's interdisciplinary, the other candidates will come from a range of backgrounds, including fields where more formal dress is the norm for the day to day.Because of the wide range, you might be better off going a little more formal/professional than normal because you will be compared to the others.

Finally, one important factor is also comfort! I also totally get that people want to be true to theirselves, instead of feeling like an imposter in uncomfortable clothes. So, whatever you choose, it needs to be a balance of your own identity and what's practical/expected. I also want to address two common concerns I get when I give advice about interview clothes:

But if the school won't accept me the way I am, then I don't want to be there!
Interviews are normally a little more formal than the day-to-day. People aren't asking you to completely change who you are. I would not feel like I would compromise my whole identity just because of one day of slightly different clothes. In addition, note that the people making the decision to admit you may not be the people that you interact with on the day-to-day so even though your day-to-day interactions might be fine with your preferred wardrobe, you need to consider who is making the decision too. If you want your best true self to have the best opportunity, it might be worth changing into something a little nicer for the interview day.

But I am so uncomfortable in anything except [my chosen wardrobe]!
Look at it another way: interviews are full of things you can't really control. What you wear is something you have complete control over and something you can decide ahead of time and forget about it. Maybe wearing some of the clothes to "practice" in the days leading up to the interview can help you feel and act more natural in them. I recommend thinking ahead about your outfit and picking something "safe" because it means one fewer thing you have to think about on the interview day. You want to be able to focus on showcasing your work, experience and talent, not being self conscious about how your outfit compares to others. Picking a middle-of-the-road outfit means you don't need to worry about being under or over dressed.

(Okay, these two questions are quite contrived and a little exaggerated but I hope it conveys some useful points!)

[cbus]

Thanks for the thorough answer!