I have a pair of 34 x 30 jeans that fit well, not too tight or loose but they are relatively baggy. I'm looking at getting a pair of slim straight jeans should I go up a size or will they fit the same way at 34 x 30?I have a pair of 34 x 30 jeans that fit well, not too tight or loose but they are relatively baggy. I'm looking at getting a pair of slim straight jeans should I go up a size or will they fit the same way at 34 x 30?

It's likely the same size will fit you, but you should be prepared to try different sizes to get the best fit. Very few people have exactly the same body shape the jeans are designed for. Also people have different preferences for how tight or loose they want their jeans to be, and that matters more when the jeans are more fitted. You probably won't need a different length, but you may need to go up, or even down a size in the waist.