How do know if trans is right for you?

I'd say forget about the labels and concentrate on how you feel.

Also you can try to forget about your clothing for a minute and think other aspects of your life. For example:
How do you see yourself in the future? will you be an old woman, man or something else?
Imagine having a kid, would you be a mom or a dad?
Imagine meeting someone new, how would you want them to see you when you first meet and how would you feel most comfortable introducing yourself?
How do you feel about pronouns and names?
Going back to appearance:
Is there things about your body that you don't feel good about?
(in my case tho, the body dysphoria kinda came only after the "social dysphoria" or what ever)
And about relationships:
Do you see you and your girlfriend as a straight or a lesbian couple?
(I found out I like girls before I realized I was also FTM trans. When ever I imagined myself in a lesbian relationship it just felt kinda off and I didn't know what the fuck was going on until I found out I was actually straight after all.)

Anyway these are just some questions I have asked myself. Maybe they'll help or maybe not. I feel like I should say tho: Questioning your gender is confusing. You're most likely not gonna find out whether you're trans or not over one night and you're probably gonna doubt your conclusion many many times and it's frustrating and what the fuck else. Good luck friend.