Now that I'm doing longer rides more often, I've been thinking that my handlebars are too wide for me. I finally measured them and they are 46cm c2c . This is on a 51cm bike and I'm 5'4". I'm not sure who thought this was a good idea but this seems exceptionally wide for this size bike.

I like being able to breath easily so I don't want to get something too narrow. Also, I'm not all that happy with my handlebar shape and was looking at the FSA Omega Compact. Would a 42cm c2c be good on these? I know they're angled out slightly towards the drops so the hoods would be closer to 40cm which I think is about what the generic formulas would put me on.

Any experience with the Omega in terms of size? I just can't believe how wide the ones that came on the bike are.

Well I'm a 5'6" male with average width shoulders and I run a 40cm 3T bar (measured by bar ends c-c). 40cm or 38cm should do you good.

if your measurements are accurate, a 46 is larger than normal as OEM equipment I would think. My CAAD9 in size 54 came with 42mm bars. you could probably go 42 or 40 with no problem, and probably some benefit.

I was shocked too, but I measured thrice. It's the Lemond/Trek in-house brand bar so I'm 99% sure it's what came on the bike (I did buy it second hand so I can't be totally sure).

I am 5' 7" and used 42cm bars for years, then got a new bike that came with 40cm bars and while I did feel a bit less stable for a while, I am now far more comfortable.

My bike came with 44's, which caused a lot of pain in my hands, neck, and elbows. Downsized to a 40cm, and it's just fine. I am 5'8" but female, although my shoulders are wider than the norm. I could probably ride 38's comfortably as well, but start running out of room to put all the various gadgets and bags

The FSA Omega Compact is ~1cm narrower at the shifter mount than the stated size. So a 42cm will be about 41cm on the hoods. The only way to know what size you'll want is to actually put your hands on some different size bars and find out which feels best to you. Finding out what size works for other people isn't really gonna help you.

This is what I was looking for. Thanks.

Width
Check width first. For optimal control and efficiency, drop handlebars should be about the same width as your shoulders (photo). These bars come in sizes ranging from about 38- to 44-cm wide. So, if the distance between the bony protrusions on top of your shoulder blades is 42 cm, that’s what the handlebar width should be.

https://www.jimlangley.net/crank/bikefit.html And lots of others out there. Search.

If they are 46cm then it sounds like they're definitely too wide for someone of your height unless you have really wide shoulders. A quick way of checking is to look at your hand position on the hoods in relation to your shoulders; if your forearms don't align then your bars might be too wide. I'm suspecting you'll probably need a 40cm, 42cm at most. I'm 5'8 and use 42cm on both of my bikes; I've tried 40cm and they did not feel comfortable.

FWIW (I'm not sure it's worth anything, but it's a little interesting), I'm 6'4", and one of my 64cm bikes came with 42cm bars. I rode with them for three or four years and felt fine. Then I ordered a supercheap set of 50cm (yes, 50) bars from Nashbar for my singlespeed, and when they came, i liked them so much I ordered another pair for my main bike. I really like the extra width. It's not easy or cheap to try a range of widths before you decide, unless you're cozy with a bike shop owner, but if you can work out a way to test-ride a bike with wider bars, you may be suprised. Anything narrower than about 46 feels cramped to me now.