All Terrain Tire Size Chart | Decode Tire Numbers

A tire size table helps you match width, sidewall, wheel diameter, and overall height so your next all-terrain set fits without rubbing.

The All Terrain Tire Size Chart below is built for the moment when a sidewall code feels like a secret language. One number changes ride height. Another changes sidewall depth. A third locks you into a wheel size. Get those parts right, and shopping gets much easier.

All-terrain tires sit in a tricky middle ground. You want trail grip and a tougher look, but you still need clean street manners, proper load capacity, and room inside the fender. That means the size on the door placard, the size on the tire, and the way your truck or SUV is used all need to line up.

This article breaks the size code into plain English, then gives you a chart of common metric sizes and a second chart that pairs popular flotation sizes with close metric matches. Use it as a starting point, then confirm fitment on your vehicle before you order.

How An A/T Tire Size Code Works

Check a sidewall marked 265/70R17 115T. That short string tells you nearly everything you need to know about the tire’s shape and carrying ability.

Width Comes First

The first number is section width in millimeters. In 265/70R17, the tire is 265 mm wide at its widest point. A wider tire can add grip and a fuller stance, but it may also need more clearance at full lock.

Sidewall Height Is The Middle Number

The second number is the aspect ratio. Here, 70 means the sidewall height is 70% of the width. Bigger sidewalls soak up bumps better and usually suit dirt, gravel, and washboard roads. Lower sidewalls sharpen steering feel, but they trim some cushion.

Wheel Size Is The Last Number

The R means radial construction. The 17 means the tire fits a 17-inch wheel. This part is fixed. A 17-inch tire will not seat on a 16-inch or 18-inch wheel.

Load Index And Speed Letter Matter Too

The 115T at the end is not decoration. The load index tells you how much weight the tire can carry when aired to the right pressure. The speed letter sets the tire’s rated top-speed class. Those marks need to stay at or above what your vehicle calls for.

P-Metric And LT Sizes Are Not The Same Thing

Two tires can share the same numbers and still feel different on the road. P-metric sizes are common on lighter SUVs, crossovers, and some trucks. They usually ride softer, weigh less, and cost less.

LT tires use a tougher casing and often suit towing, cargo, rocky trails, and lower off-road pressures better. The tradeoff is weight and ride feel. A 265/70R17 P-metric tire and a 265/70R17 LT tire may fit the same wheel, yet one can feel calmer on pavement while the other shrugs off abuse better.

Why This Matters Before You Order

Size alone does not settle the choice. Load range, tread depth, casing weight, and the job your vehicle does each week all shape what will feel right after the install.

What Changes When You Size Up Or Down

A jump from 265/70R17 to 285/70R17 does more than make the tread wider. The tire usually gets taller too. That can raise ground clearance, fill the wheel well, and add a softer hit over rocks or broken pavement. It can also bring rubbing at the liner, mud flap, sway bar, or upper control arm.

Going taller may trim fuel economy, soften braking feel, and nudge the speedometer off a bit. Going heavier can do the same. On many trucks, a modest move works fine. A big move may call for trimming, a lift, new wheels with a different offset, or all three.

How To Choose The Right Size Before You Buy

Start with the tire placard on the driver’s door or the owner’s manual. That gives you the factory size and pressure range for your trim. NHTSA tire safety guidance says replacement tires should match the original size or another size recommended by the vehicle maker.

• Use the stock size if you want the least drama.
• Size up one step if you want a fuller stance with a better shot at stock-like fit.
• Check load index before tread pattern, sidewall style, or brand.
• Check wheel width range for the tire you want.
• Leave room for full steering lock and full suspension travel, not just a parked photo.

Then read the sidewall code the same way tire makers do. Bridgestone’s tire size explainer lays out the same order: width, aspect ratio, construction, wheel diameter, then service description.

All Terrain Tire Size Chart By Popular Metric Sizes

The chart below uses the size formula to show calculated overall diameter. Brand specs can shift a little, but these figures are close enough to sort stock-friendly sizes from taller upgrades.

Size	Calc. Diameter	Where It Often Fits
235/75R15	28.9 in.	Older SUVs and compact 4x4s
245/75R16	30.5 in.	Midsize trucks and SUVs
265/70R16	30.6 in.	Half-ton trucks and body-on-frame SUVs
265/75R16	31.6 in.	Older off-road builds chasing extra sidewall
245/65R17	29.5 in.	Crossovers and lighter SUVs
265/70R17	31.6 in.	Stock-friendly upgrade on many trucks
275/70R17	32.2 in.	Mild lift or roomy factory fitments
285/70R17	32.7 in.	Common 33-class choice for trucks and Jeeps
265/65R18	31.6 in.	Late-model trucks and SUVs on 18s
275/65R18	32.1 in.	Another step up for newer 18-inch setups

What The First Chart Tells You Fast

Wheel diameter alone does not tell you whether one tire is bigger than another. A 265/65R18 and a 265/70R17 land in nearly the same height class even though one fits an 18-inch wheel and the other fits a 17-inch wheel. That is why shoppers get tripped up when they chase wheel size instead of overall diameter.

There is another pattern here too. Many stock truck sizes cluster around the low-31-inch range. Once you push into the 32s and 33s, clearance questions start showing up more often, even when the wheel diameter stays the same.

Flotation Sizes And Close Metric Matches

Some all-terrain tires use flotation sizing such as 31×10.50R15 or 33×12.50R17. The first number is overall diameter in inches, the second is width in inches, and the last is wheel size. The metric match is a class match, not a perfect twin, but this chart gets you close.

Flotation Size	Close Metric Match	Notes
31×10.50R15	265/75R15	Classic 31-inch fitment with a full sidewall look
33×10.50R15	255/85R16	Tall and narrow, handy when width is tight
33×12.50R15	285/75R16	Wide 33-class setup with a chunky stance
33×12.50R17	285/70R17	One of the most common truck and Jeep jumps
33×12.50R18	295/65R18	Close match for trucks already on 18-inch wheels
35×12.50R17	315/70R17	Big step that often needs extra clearance work

Common Mistakes That Lead To A Bad Fit

Most fitment trouble starts when shoppers watch only the first number or only the wheel diameter. Width, wheel offset, and shoulder shape can matter just as much. One brand’s 285 may run wider than another brand’s 285. Side biters can touch sooner than a smoother shoulder design.

Pressure can trip people up too. The max PSI printed on the sidewall is not a daily target for every truck and every load. Start with the placard, then tune from there if your tire maker gives a range that fits your use.

Run Through This Check List

• Door placard size and cold pressure
• Wheel width and offset
• P-metric or LT construction
• Load index that meets the vehicle’s needs
• Clearance at full lock and full suspension compression

Reading The Chart For Your Own Rig

If you daily-drive a stock midsize truck, the sweet spot is often one step up from factory, not three. If you tow, haul gear, or spend weekends on jagged rock, an LT tire with the right load rating may fit your needs better than a lighter tire in the same size.

The best size is the one that fits your wheel, clears the body, carries the load, and matches the way the truck is used. A taller tire is not always the better tire. A lighter, easier-fitting size can ride better, brake shorter, and cost less to live with over time.