How long will it take to finish universal studios LA?

we have 2 days planned to go to universal studios but we were wondering if we could finish it in a little over a day because we want to go to other places like chinatown...

You can definitely do Universal in a day. Arrive early, take the first tour tram out, and then ride the rides and see the shows the rest of the day. Go to City Walk for lunch. The food's cheaper, and you have more variety. I personally like Tony Roma's, but my kids like Cafe Tu Tu Tango and Hard Rock Cafe. Since they do research for me in this forum, they told me I have to give those places equal billing.

A day if there no long lines

if you are there when they open, you should have plenty of time in one day. i think you will even be able to stroll through city walk which is right there too.
go on the tram first, that line gets the longest.

It all really depends on what you want to see and do. Get there before they open and try to get on the rides ASAP and hopefully you can get it done in one day.

Takes about 3 hours or so, maybe a bit less, but worth every minute.

It is definitely do-able in one day. It really isn't like the other theme parks where you need tons of time to do it all. If you get there when they open you will have plenty of time to see it all, leave a little early, grab a bite to eat at city walk and be in bed by curfew