Im looking at getting a new wheelset and im not sure on what width i need. Current tires are 700cx28 schwable durano tires. I looked at a tire matrix and it says 19mm wide? Wheels i have seen are 23 and 25 mm wide.So what would be the best width. Thanks

You have two things to check. First, that the tire and rim combo works. You usually want a wider tire on a wider rim. For example, when we got rough chip and seal roads around here, I went to a 700x25 tire on a Velocity A23 which is 23mm wide. I had previously ridden 700x23 tires on Mavic Open Pros which are only 19.6mm wide. You can get an even wider rim for wider tire sizes, but you need to check the mfg's recommended rim size for the tire you want to ride.

The second thing to check is your brakes. Some types of calipers won't open wide enough to easily get the inflated tire in or out. Some mfg's will recommend a maximum tire size for their brakes. If you're running disc brakes, this obviously doesn't matter.

The 700x28 tires you have will likely work well on 23 or 25mm rims.

You may see ETRTO charts that show a rim width to tire size recommendation. Those numbers are the inside dimensions of the rim where the tire seats, not the brake surface width we more commonly use when talking about rim widths.

Thanks brakes are disc.

I run 42mm tires on A23 and it works quite well. A wider rim would do two things, one is make the tire effectively wider, the other is to allow lower pressures to be run without the tire rolling on the rim in hard corners. For me, that happens at about 25psi under my 220 lb, so not much of an issue.

On a racing bike, theory has it that a wider rim with a wider tire forms a smoother teerdrop shape. But if you just want something that works, it is almost a non issue.

Yeah, this is virtually a non-issue, as virtually all road tires will fit any road rim securely. There are extreme and unusual combos which might cause concern, like trying to stretch Conti GP Attack 22c tires across 30.2mm bead seat width Belocity Blunt 35s, but then, why would anyone do that? (I run 26.6mm bsw Blunt SE rims on the road with 28c Vittoria Randonneur Pros on my commuter/ute; sweet setup!)

And as mentioned earlier, "rim width" is not the critical measurement in tire fit security questions. You need to know the bead seat width, or inner width. Outer width can be important for caliper brake users pushing the width limits, can describe the way the sidewall will sit in relation to the brake track, and give insight into rim durability, bit it's irrelevant to tire retention and shaping.

In general, higher rim BSW/tire width ratio will enhance handling. Fat tires on narrow rims are more likely to deflect the sidewalls under side loads (i.e. cornering).