I first decided to buy an ATV a few years after I sold my truck. Of course one of the biggest hindrances to buying an ATV was figuring out how to haul it. Unless you live on some decent land where you can drive your ATV, it will not do much good for you unless you have a way to haul it to where you want to ride it. For me, this meant buying a truck and potentially a trailer. I thought it would be great to start out if I did not need a trailer and could fit an ATV in the bed of a new truck, but then, my wife wanted an ATV even more than me, and then the kids want their own. In the end, I needed some ATV dimensions. That, obviously, is the first step to figuring out what you need to haul an ATV, so I did some digging.
ATV sizes are not uniform in the least. That being said, there are some definite trends. Obviously, the bigger engine size you get, the bigger the ATV will be. Children or youth ATVs are generally going to run fifty to sixty inches long and thirty to forty inches wide. Smaller ATVs are generally going to be sixty-five to seventy-five inches long and forty to forty-three inches wide. Your standard and most popular sized ATVs are generally seventy to ninety inches long and forty-two to forty-eight inches wide. Finally, your larger ATVs are going to be a little larger at seventy-four to ninety-four inches long and 46-48 inches wide.
Before I get into the more specific dimensions for each class of ATVs and UTVs, there are a couple of key trends I noticed in analyzing the dimensions of hundreds of different ATVs. First, the sport models made by each manufacturer are typically a little smaller than the utility models. Second, the longest machines were not always the widest so it is not just a matter of finding the biggest or smallest ATV. Third, 48 inches wide seems to be the golden number where you can pretty confidently plan on that being your maximum width on any ATV you find.
50cc ATVS
The 50cc ATV is the smallest sized ATV and is typically used for smaller children. The smallest 50cc ATV I came across was the 
Polaris Predator 50. These small machines have equal dimensions at only 31.5 inches wide and 48 inches long. If you are just going by width, however, the narrowest 50cc ATV is actually the Suzuki Quadsport Z50, which is only 29.9 inches wide despite being 50 inches long. The largest 50cc machine I came across is more difficult to determine because the longest was not the widest. The longest machine is the Yamaha Raptor 50 at 60.5 inches long, but only 32.5 inches wide. The widest 50cc ATV was the Kawasaki KFX 50 at 34.7 inches wide and 55.1 inches long. Overall, the 50cc machines I reviewed ranged from 48 to 60.5 inches long and 29.9 to 34.7 inches wide.
70cc ATVS
70cc ATV’s are far less popular than the 50cc or 90cc models, but they can be found. The most popular 70cc model is the Can-Am DS70, which is 48 inches long by 35.6 inches wide. More 70cc models can be found that are typically Chinese imports and lesser known brands such as the Raceway XL 70, which is 44 inches long and 26 inches wide.
90cc ATVS
90cc ATVs are one of the more popular-sized youth ATVs. Probably the smallest 90cc ATVs are going to the Sport DVX 90 or Utility Youth 90 from Arctic Cat, both of which are 57.8 inches long by 34.5 inches wide, or the Kawasaki KFX 90, which is 56.1 inches long by 35.6 inches wide. The KFX 90 is going to be the shortest machine at 56.1 inches long. The least wide machine, just barely, is the Suzuki Quadsport Z90, which is 34.4 inches wide. The longest 90cc ATV I found was the Polaris Sportsman 90 at 61.5 inches long by 38.5 inches wide. On the other hand, the widest, by a decent margin, was the Yamaha Raptor 90, which is 40.2 inches wide. Overall, the 90cc ATVs I reviewed ranged from 56.1 to 61.5 inches long and 34.4 to 40.2 inches wide.
200cc ATVS
The 200cc ATV is another size that is not as popular in the United States. Most of the models you are going to find are lesser-known brands and/or imports from China. There are a handful of popular models; however, including offerings from Polaris and Yamaha. The biggest 200cc ATV is the Bombardier Rally 200, which is 79.9 inches long and 41.5 inches wide. The shortest model is going to be one of the two Polaris models, the Phoenix 200 or the Saw Tooth, both of which are 65 inches long. The least wide model is the Yamaha Blaster, which is 40.7 inches wide. Overall, the vast majority of machines at 200cc are going to 65-70 inches long, with the Bombardier Rally being the outlier at 79.9 inches long. The width is going to be between 40 and 42 inches wide on most models.
250cc ATVS
At the 250cc size, we start getting back into the more popular offerings. The biggest 250cc I found was probably the Yamaha Big Bear 250, which was 75.4 inches long, but only 40.9 inches wide. The widest machine would be the Arctic Cat DVX 250 or Honda TRX 250EX, both of which are 41.8 inches wide. The least wide model is the Kawasaki Bayou 250, which is 40.2 inches wide. The shortest machine I found was the Arctic Cat DVX 250, which is only 66.3 inches long. Overall, the 250cc ATVs are likely to range from 66 to 76 inches long and 40-42 inches wide on most models.
300cc ATVS
I have only seen a couple 300cc ATVs from the more popular ATV brands. Polaris makes the Hawkeye, which is 72 inches long and 42 inches wide. Arctic Cat also makes a 300cc machine that is 73.6 inches long and 41.4 inches wide. Given that, I think it is safe to say you can expect a 300cc ATV to fall between 70 and 75 inches long and 40 to 42 inches wide.
350cc ATVS
The 350cc class is dominated by Yamaha from what I was able to find, but there are a few other options as well. The biggest option, in both length and width, is the Arctic Cat 350. That machine is 83.3 inches long and 44.5 inches wide. The shortest model is the Yamaha Raptor 350, which is 69.7 inches long. The least wide 350cc ATV is the Yamaha Wolverine 350, which is 41.9 inches wide. The 350cc ATVs range in length from 69 to 84 inches, but the majority seem to be around the 76-79 inch range. The width range is much smaller, ranging from 41 to almost 45 inches.
400cc ATVS
400cc is where we start getting into the normal range of adult ATVs and we see more options to compare. At 400cc, the Arctic Cat 400, which is the utility model for Arctic Cat, is by far the biggest ATV. It is 84.3 inches long and 47.8 inches wide. By comparison, the DVX 400 sport model from Arctic Cat is the shortest ATV of this class at just 72 inches long. The least wide model is the 41.5 inch-wide Bombardier Outlander 400 HO. Overall, the 400cc ATVs range from 72 inches to 84.3 inches long and 41.5 inches to 47.8 inches wide. The models I reviewed dotted pretty much everywhere in that range without any real consensus.
450cc ATVS
At 450cc, we get even more options from the likes of Honda, Kawasaki, Polaris, Yamaha and Can-Am. The largest 450 cc ATV I found was the Polaris Sportsman 450, which came in at 83 inches long and 48 inches wide. The shortest model was the Kawasaki KFX 450R at 71.1 inches long. The least wide ATV was the Yamaha Wolverine 450, which is only 41.9 inches wide. As such, the 450cc ATVs range from 71 to 83 inches in length and 41 to 48 inches in width. Most of the models I saw fell in either the 71 to 73 inches or 77 to 83 inches ranges in length, with almost none in the 74-76 inches long range. In width, the 450cc ATVs ranged from 41 to 48 inches, with most sitting around 46 inches wide.
500cc ATVS
The largest ATV at 500cc that I found was the Polaris Sportsman 500 X2 EFI, which is 93 inches long and 48 inches wide. That ATV just barely edges out the Arctic Cat 500TRV Plus, which is also 93 inches long, but only 47.5 inches wide. The longest machine is the Bombardier Outlander 500 HO, which is a whopping 94 inches long. Surprisingly, this ATV from Bombardier is also the least wide ATV at only 46 inches wide. The shortest 500cc ATV is the Polaris Outlaw 71.5 inches long. The 500cc ATV class is where we see a wide range of lengths among the popular ATVs, ranging from 71.5 to 94 inches long. The width, on the other hand, is pretty consistent among 500cc ATVs, almost all falling between 47 and 48 inches wide, with the Bombardier being an outlier at 46 inches wide.
650cc ATVS
The 650cc ATV class sees less range than the 500cc ATVs. The longest machine is once again 94 inches long in the Bombardier Outlander 650 HO. That model is also the least wide at 46 inches wide. The shortest 650cc ATV is the Bombardier DS 650X, at just 77 inches long. That machine also happens to be the widest at 48 inches wide. At 650cc, most of the ATVs are 84 to 94 inches long, with the outlier Bombardier ATV at only 77 inches long. As to width, most of the machines are in the 47-48 inches range, with a couple dropping down to 46 inches wide.
700cc ATVS
Among the 700cc ATVs, there is a bit more range, from the shorter Yamaha Raptor 700R, at 72.6 inches long, to the Arctic Cat 700 Diesel, at 93 inches long. The least wide model was the Yamaha Raptor 700R, at just 46.1 inches wide. The widest model was the Polaris Sportsman 700 EFI, at 48 inches wide. The length of the 700cc ATVs went from 72 to 93 inches, but most of the machines were in the 82-85 inch range. For width, all the machines were in the 46-48 inches wide range. Notably, all the Arctic Cat models came in at 47.5 inches wide.
800cc ATVS
The 800cc class of ATVs is fairly limited and mainly limited to Bombardier and Polaris. They both have a smaller and larger model. The Bombardier Renegade 800 is 86 inches long and 46 inches wide. The Bombardier Outlander 800 is the larger model. While still 46 inches wide, the Outlander is 94 inches long. The larger Polaris is the Sportsman 800 X2, which is 93 inches long and 48 inches wide. The smaller Sportsman 800 is only 83 inches long and 48 inches wide. I would also throw the 750cc Kawasaki Brute Force into this class. It is 86.4 inches long and 46.5 inches wide. With this limited selection, you can expect 800cc ATVs to be 83 to 94 inches long and 46 to 48 inches wide. Again, there seems to be shorter and longer models without a lot in between.
1000cc ATVS
The king of the class is the 1000cc ATV. As you would expect, your ATVs are going to be big at the 1000cc size. The smallest of the bunch that I found is the Arctic Cat 1000, which is 84.8 inches long and 47.5 inches wide. The biggest that I found is the Arctic Cat MudPro 1000, which is 94.5 inches long and 47.8 inches wide. The machines I found at 1000cc ranged from 84 to 95 inches long and 46 to 48 inches wide.