odd potty behavior

I don't know if anyone else have male cats that are fixed that seem to urinate on the side of the litter box? At first, I thought that my litter pan had a hole in it until it happened in the other box they also use. It's rather strange behavior I think, especially when the rest of the box is clean. Does anyone have any ideas as to why both my cats are doing this? Actually, it might just be the 1, not exactly sure lol. I have thought of only 1 solution to this problem, to get a covered litter box, that way they won't be able to pee on the side of the box!!!

I have a female cat that does this!  She just doesn't always squat enough so she pees either on the side or on the edge of the box; leaving a mess for us to clean up.  The best fix for this seems to be just higher sided boxes.  Ours is pretty tall already; but lowered in the front for easier entrance.  Plastic storage totes are another good option and they come in a variety of sizes.  A covered box might work; but I've heard people comment that their cat pees through the crack where the top meets the bottom.  I have always used open top boxes; so I'm not familiar with the designs that are out there right now. 

Ritz (Female) pees standing up about 75% of the time, always has. I went through several types of boxes. Covered ones didn't work because the urine would seep through the cracks. I finally settled on a LARGE plastic container, about 17 to 19" high; she has to jump in to pee. (An opening at the side of the box didn't work, her urine would go out there too).

I purchased high rim litter boxes to avoid the over the top pee'ers. Natures Miracles have a perfect triangle high sided litter box which I have 6. They are oversized and high walled. I have one that insisted on peeing on the side no matter how high or low the litter is. I tried everything. I just decides that at least there no more pee flying over the side so now I'm happy.

It could be one of them is actually having problems getting into the litterbox due to age becuase the ledge is too high. If one of your cats is older it seems sometimes they take all their strength to get in because of joint issues that they don't keep moving into the litterbox before peeing resulting in a quarter of it landing in the litterbox and the rest outside. I ultimately had to buy a huge litterbox and put it out in the garage. It was a infant baby pool I converted to a litterbox by cutting down one side so they can walk in. It sounds huge but the infant size isn't too too big. If all else fails going the opposite with low walls but very big area may work.