Dimensions of Mudguard suitable for Fuji Absolute 1.9D 700mm or26.5 inch tyre
I'm going to try and answer generically.  You can apply this to your own bike.

A mudguard/fender has one main task, to stop water and muck from transferring from the tyre/tire to the bike and the rider.

ROAD

So, the best-performing mudguards you can buy will be "full" ones, something like this:



Points to note:


guards are pretty close to the outside of the tyre.
front edge of rear guard goes right down to the bottom bracket.  This protects a lot of the bike's transmission
rear edge of rear guard trails behind the whole bike - its a good place for mounting lights and reflectors.  Also protects other cyclists behind you from the taste of road water.  
front guard is only a quarter circle, but there's nothing in front of you to protect.
front guard also allows the suspension to work as normal.
neither guard messes with the function and performance of the brakes, whatever is on the bike.
both guards are supported by two additional struts, as well as the brake mount point and the rear's chainstay mount.  More support means less rattling.


Materials - some people prefer plastics, some chromoplastics (plastics that look like metal) and there's also steel and aluminium/aluminum options.  Probably have a hard time finding carbon fibre/fiber ones, but they may exist.



MTB

These ones are primarily for off road or muddy use.  They flap around a bit more, weigh less, and catch a lot more air.  They also tend to snap off in any form of accident, which is not altogether bad but they're also not overly durable.  Almost always made of plastic, these MTB ones don't have a lot of support other than one bolt or clamp.

MTB ones may not provide a lot of protection for the drive chain - this picture has an additional one down low on the rear wheel, but in really serious mud this could clagg up with grass and pog.

Significant plus is that these are a lot cheaper than full guards.






Emergency

This is an Ass-Saver (tm) (etc)   There are many emergency guards, but this one has the cheesy name.
They clip into the saddle rails and jutt out the back.  That's all.

They're short but on a road bike that's okay.  Downside is that they're so far from the wheel that roadspray still flies up and hits me in the back of the thighs anyway.  These also do nothing to protect the bike or the components of brakes or transmission.  For a tenner they're overpriced.





I've also been known to slip a medium flattened cardboard box between my back-side and the saddle.  It worked.  This chap has wedged cardboard in the back seat stays.
  

If you have a rear carrier, you can put a layer of cardboard or reuse something made of plastic.  This is what I have on my wetbike, and it works well enough, no photo sorry.