![actual size of 33 inch tires actual size of 33 inch tires](https://i.ytimg.com/vi/O6QqdqFjc-E/maxresdefault.jpg)
![actual size of 33 inch tires actual size of 33 inch tires](https://toolstastico.com/wp-content/uploads/2018/09/Jeep-Wrangler-Tires-Size-Chart.jpg)
For those math phobes out there, don’t worry! It’s not that complicated! To get started let’s use a size from the chart above, we’ll go with 295/30R26. So, whether you’re upsizing or switching to LT sizes, the first thing you’ll need to do is calculate your tire’s overall diameter (or OD). That way you can still figure it out if you’re stuck without a converter and you can tell if the converter you’re using is a bit off. However, it’s still a good idea to have at least a basic understanding of how to do it yourself. So what if you want to put these tires on your car? Or, if you already have them, what if you want to upsize them? Or what if you have these tires and want to switch back to metric? You could use a converter like this or you can even find a chart like this one: Tire Conversion It’s an important distinction, because you might get a tire that says 35 and measure it, uninflated, around 33 or 34 inches and think you have room to work with when you actually don’t. It also means that the overall diameter will be different from the diameter of the tire when it’s not inflated. This means that the tire is on a rim and inflated to pressure, but without any weight on it. You see, overall diameter measures the diameter of the tire after it’s inflated but before it’s put on a vehicle. This is also why it’s important to understand overall diameter, or the number measured in the first part of the tire size. This is especially handy with the off road tires, as they tend to have a deeper, chunkier tread than other tires. Having the diameter lets you figure out how much clearance the tire will have in your wheel well. This type of size measurement is very useful for these types of tires.
![actual size of 33 inch tires actual size of 33 inch tires](https://cdn.discounttire.com/sys-master/images/hfb/hcf/8805702991902/EDUtire-size-check_tire-size-check_hero.jpg)
We’ll get into the reasons for this in just a bit. You can hear it referred to as LT, Numeric, Wide Base or Floatation sizes. The first thing you should know about LT sizes is it has many names. Well we’re here to take away some of the confusion, so let’s get right down to it: WHAT IS AN LT TIRE SIZE? LT sizes can be confusing because they’re so different from the sizes you’re used to seeing. But there’s another system of sizing out there, LT Sizing, used primarily for light truck and off road tires.
![actual size of 33 inch tires actual size of 33 inch tires](http://tireworx.ca/wp-content/uploads/2016/09/tire-sizes.jpg)
These are the sizes most of you are probably familiar with, such as 205/55R16. Most passenger tires today have metric or “P-metric” sizes.