advice on guage sizes

I am going to be new to model railroading, because i will be helping my grandson build a railroad. Can anyone assist me as to a guide to guages
Is there a guide anywhere on line that i can see the differnt sizes?
Thanks.

There’s a fairly stock picture MR runs every time they run an “intro to scales” article - it might be available to view on the main Model Railroad page. It shows the relative sizes of the different scales.
If it’s mainly for your grandson - a key facotr in chosing a scale is how old he is, and how he tends to handle his other toys. The smaller scales are naturally more delicate and tend to require more motor skills to rerail cars and locomotives, and are generally not suitable for younger children.
‘Generally’ because it depends a lot on the child, I have seen 5 year olds that are more ‘mature’ than some 8 year olds.

–Randy

HO is a good scale to look at - plenty of “support” in the form of kits, trackwork, structures, etc out there. I would say that the child’s age matters less than how they handle the stock - agree with Randy on this one. My younger brother was bought his first N-scale set at the age of three, never broke anything, in fact we still have the two freight cars from that set (loco broke, though that was more due to poor build quality than the owner’s age)! Another thing to bear in mind is that not all HO is the same - for example, a BLI steamer has lots of delicate fine detail that would not stand up well to smaller hands, but an Athearn “Blue Box” diesel has metal handrails and is generally “hardened” - they will survive events that will finish a more expensive and upmarket loco and will also run for years. Hope this is of help!

[#welcome]
I would recommend you and your grandson go to a train show that has layouts in the different scales/gauges displayed. Pictures on the interent will show you relative sizes, but actually seeing some trains running will give you a better idea of what the actual sizes are.

Enjoy
Paul