I'm trying to find the handle size for various (current model) Shimano casting reels.  I can't seem to find it on the Shimano website.

 

I have found it for JDM reels, but I'm not confident that the US and JDM reels are exactly the same.

Which reels specifically are you interested in knowing the handle size for?

Get yourself a ruler with Millimeters (mm) markings on it. Measure from the center to center of the handle shank/shaft and that will give you what you are looking for.

Call Shimano tell what reel you have & ask what handles fit.

I think everybody is missing the OP's point - what length handle comes on new reels is not reported by Shimano USA. 

My thought is JDM will be equivalent - they don't sell different reels here, they just export fewer models to USM. 

Easy for me, every reel gets a new handle I prefer, and tune length to the gear ratio. 

Ebay seller SDScustom is a cost-effective source. 

23 hours ago, Maico1 said:

Get yourself a ruler with Millimeters (mm) markings on it. Measure from the center to center of the handle shank/shaft and that will give you what you are looking for.

I would if I owned the reel. I'm going to buy some new reels and would like to know what size handle they come with before buying them. They aren't in stock anywhere locally so I have no way of getting my hands on one. 

Just now, TNReb said:

I would if I owned the reel. I'm going to buy some new reels and would like to know what size handle they come with before buying them. They aren't in stock anywhere locally so I have no way of getting my hands on one. 

I’m not sure if handle length matter when considering buying a reel, but if you specific model some of us might be able to tell you. Also there plenty of handle length either from Shimano or third party (carbon fiber handle) that you can upgrade with not much more.

Most of Shimano reel start with 84mm handle, then some newer like K or SLX come with 90mm and if XG model get even longer 96mm handle. Most if not all Shimano handle are interchangeable in between each model and can be find easily. 

Type whatever model it is you want to know then handle length in google search

I don't even know what "handle size" means.

 

I've never found a reel that didn't fit onto all my rods I've tried them on.  I'm not sure what the point of this is.

Some are picky than others, I guess. I don’t really care much about handle size or knob per se. But when it come to my lefties I have to have 90mm handle to be able to crank smoothly.

I dunno, I just prefer a longer reel handle, makes cranking for me a bit easier. I've switched all of mine out to longer handles.