YOu need to specify which square taper BB. There are various square taper BB designs out there and they are not all cross-compatible.

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If you are ok with your FSA square taper cranks you can buy another set in 172.5. A quick Google search for FSA Vero Compact 172.5 brings up a lot of online purchase options.

The square taper cartridge bottom bracket can probably be replaced by any English threaded 68mm bottom bracket. If you want to switch to a two piece crank instead of 3 piece square taper I'd suggest going Shimano or Sram GXP. There are so many two-piece crankset and bottom bracket combos offered by FSA that it is hard to keep them straight.

The bottom bracket will say the size on it when you remove it. 68x113 as an example. 68 is the shell size, 68mm. That's all you need to know, it should be 68mm or 73mm.

Then, just buy the correct bottom bracket for the crank that you want in that size.

Why not change to an updated English BB?

The new Ultegra or 105 4arm crankset is nice and allows versatile chainring setups and can be had pretty cheap including the BB

I know it is JIS Square taper, but I was hoping to replace the bottom bracket. I was trying to see if anyone knows the correct size so that I can order with our having to take apart now.

Square taper style= ISO or JIS (not important if you're going to a new system).

English 68 or Italian 73. Most likely you have an English threaded BB double check.

Width will be important for new systems, it's based on chainstay clearance. If your JIS BB is 109 or less, you can probably accept GXP, shimano, or MegaExo double check though

Thanks for the info. Seems like I just need to take apart to figure out the right size before I order.