Ram 1500 Tire Size Guide: OEM, Plus-One & Off-Road Options by Year

You're standing in the tire shop parking lot, phone in hand, staring at a 2021 Big Horn on 20-inch factory wheels. The tech asks what size you want. You have no idea. The sticker inside the door jamb is faded past reading. Bad spot to be in. I've watched owners waste an hour on that exact problem because shop databases listed two fitments for their year. This guide shows you the factory size for every Ram 1500 generation, when a plus-one upgrade works, and which off-road sizes fit without a lift.

Most Ram 1500s leave the factory on tires between 245/70R17 and 275/55R20. The Tradesman runs 245/70R17. Big Horn steps up to 265/70R17 or 275/60R20. The Rebel rolls on 33-inch LT275/70R18 Goodyear DuraTracs. The TRX wears 35-inch LT325/65R18 Goodyear Territory MTs. Most stock Ram 1500s clear a 33-inch tire (285/70R17) without a lift. Anything 35 and up needs at least a level.

Ram 1500 Factory Tire Sizes by Year and Trim

Ram has built the 1500 across three generations since 2002. Factory tire sizes shifted with each redesign. The third-gen trucks (DR/DH platform) ran smaller fitments. The fourth-gen DS trucks added the 20-inch wheel option. The fifth-gen DT trucks brought 22s into the mix and pushed the Rebel and TRX into real off-road rubber.

To verify a specific build, check the Ram spec page. Here's the working chart most owners need.

Generation	Years	Trim	Factory Tire Size	Wheel
Third (DR/DH)	2002-2008	ST / SLT	245/70R17	17"
Third	2002-2008	Laramie	265/70R17	17"
Fourth (DS)	2009-2018	Tradesman	245/70R17	17"
Fourth	2009-2018	Big Horn	265/70R17 or 275/60R20	17" / 20"
Fourth	2009-2018	Laramie / Longhorn	275/60R20	20"
Fourth	2013-2018	Rebel	LT285/70R17	17"
Fifth (DT)	2019–present	Tradesman	265/70R17	17"
Fifth	2019–present	Big Horn	275/65R18 or 275/55R20	18" / 20"
Fifth	2019–present	Laramie	275/55R20	20"
Fifth	2019–present	Limited	275/45R22	22"
Fifth	2019–present	Rebel	LT275/70R18	18"
Fifth	2021-2024	TRX	LT325/65R18	18"

Match your VIN year and trim before calling the shop. Going by year alone gets you the wrong size half the time, because Ram offered two or three wheel choices on most mid-trims.

How to Read a Ram 1500 Tire Size Code

A code like 275/60R20 looks like alphabet soup until you break it apart.

• 275 is the section width in millimeters. That's how wide the tread footprint is.
• 60 is the aspect ratio. The sidewall is 60% of the section width, roughly 165 mm tall.
• R means radial construction. Every modern Ram tire is radial.
• 20 is the rim diameter in inches.

You'll also see an LT prefix on Rebel and TRX tires (LT275/70R18). LT stands for Light Truck. These tires run higher load ratings and stiffer sidewalls, which is why off-road trims get them from the factory. P-metric tires (just "275/60R20" with no prefix) are the standard passenger setup on most Tradesman, Big Horn, and Laramie builds.

Open the driver's door and look at the sticker on the door jamb's inner edge. It lists tire size, cold inflation PSI, and max load. That sticker beats any internet chart for your specific VIN.

Plus-One Tire Upgrades for the Ram 1500

Plus-one means you go up one inch in wheel diameter and drop the tire's sidewall height to keep the overall diameter close to stock. The truck looks more aggressive. Steering response sharpens. The speedometer stays accurate.

What Plus-One Actually Changes

The trade-off is ride comfort. A shorter sidewall transmits more road texture to the cabin. On a half-ton truck that already rides firm, that's a real consideration. Most owners who went plus-one on a Big Horn say the visual payoff is worth it. A few wished they'd stayed stock after the first winter pothole season.

Load rating matters too. If you tow or haul, the upgrade tire needs to match or exceed the factory load index. Drop below it and you've got a payload problem.

Recommended Plus-One Fitments by Stock Wheel Size

Stock Setup	Plus-One Upgrade	Overall Diameter Change
265/70R17	265/65R18	-0.1"
275/60R20	275/55R21	+0.1"
275/65R18	275/60R19	-0.2"
275/55R20	275/50R21	-0.1"

Keep the overall diameter within 3% of stock and the speedometer reads correctly. Push past that and you'll need a recalibration or a programmer.

Off-Road Tire Sizes That Fit a Stock Ram 1500

On a stock Ram 1500 with no lift, you can fit a 33-inch tire. That's the ceiling on the standard suspension.

The proof is the Rebel. It rolls off the factory line with 33-inch LT275/70R18 Goodyear DuraTracs and clears them with no rubbing, full lock-to-lock, full compression. Same body, same fender wells as the Big Horn. If Ram clears 33s from the factory on the Rebel, you can clear 33s on a Big Horn or Laramie with the same wheel offset.

The fitments that work on stock suspension:

• 17-inch wheels: 285/70R17 (33.7")
• 18-inch wheels: LT275/70R18 (33.2"), same as Rebel
• 20-inch wheels: 295/60R20 (34"), borderline on tight turns

What about 35s? You'll rub. The front upper control arm contacts the tire at full lock. The rear inner fender liner catches on compression. A 2-inch level plus trimming the mud flaps gets most builds there. A full 4-inch lift does it clean.

The TRX is the exception. It runs factory 35s on a totally different suspension and widebody fender flares. Don't compare TRX clearance to anything else in the lineup.

Ram 1500 Rebel and TRX Tire Sizes

The Rebel and TRX both wear LT-rated tires from the factory. That's not marketing. Both trucks were built to actually leave pavement. A P-metric tire on a 6,000-pound truck pounding a washboard road folds sidewalls.

The Rebel runs LT275/70R18 Goodyear Wrangler DuraTrac at 33.2 inches tall. The 18-inch wheel is beadlock-capable on the upgraded package, which matters if you air down for sand or rocks. Most Rebel owners who upgrade go to a 34-inch or 35-inch all-terrain after a 2-inch level. BFG KO2s in 285/75R18 are the popular swap.

The TRX runs LT325/65R18 Goodyear Wrangler Territory MT at 35 inches. That's a mud-terrain, not an all-terrain. The Territory MT is a softer compound built for the TRX's Baja-style mission. Owners replacing them at 25,000 miles aren't surprised. Soft compound, heavy truck. Common upgrades: Nitto Ridge Grappler 325/65R18 or BFG KM3 in the same size.

Tire Load Rating and Speed Rating Explained

The numbers after the size string (like 275/60R20 115T) tell you load capacity and speed limit. Skip these and you can undersize a tow rig.

Most half-ton Ram tires run load indexes in the 110 to 116 range. That translates to roughly 2,337 to 2,756 pounds per tire. Four tires at 116 carry over 11,000 pounds combined. This is what gives the Ram 1500 its 7,000-plus pound max tow rating room to breathe.

Speed ratings on Ram 1500s are usually S (112 mph), T (118 mph), or H (130 mph). Performance trims like the older R/T pushed up to V-rated tires. For a stock work truck or family hauler, T is plenty.

When you replace tires, match or exceed the factory load rating. The door jamb sticker shows it. Drop one step down and your insurance company gets interested if you have a payload-related incident.

Seasonal Tire Options for the Ram 1500

Most Ram 1500s leave the dealer on all-season tires. Fine for daily driving in moderate climates. Bad for two specific use cases: serious snow and serious dirt.

All-terrain is the right call if you split time between pavement and unpaved roads. Popular factory-size all-terrain options:

• BFGoodrich All-Terrain T/A KO2, available in 265/70R17, 275/65R18, 275/60R20
• Falken Wildpeak AT3W, available in nearly every Ram factory size, snow-rated
• Toyo Open Country A/T III, strong wear life, runs quiet

For winter-only use, many Ram owners run a dedicated winter wheel-and-tire package. Drop one inch in wheel diameter (20-inch stock to 18-inch winters) and one step narrower in section width. A 265/70R18 winter tire on an 18-inch steel wheel gets you better snow traction and protects the factory 20s from road salt. Blizzaks, Hakkapeliittas, and Firestone Winterforces all come in Ram sizes.

Keeping Your Ram 1500 Interior in Shape While You Work the Tires Hard

A truck built to run 33s on a muddy two-track takes interior punishment too. I've seen a 2022 Rebel come back from a Moab trip with mud baked into the factory cloth on the driver's bucket. The kind of stain that sets before you get home. Cleaning didn't get it out. Reupholstery quote was over $800 per seat.

Tailored seat covers solve that before it happens. Our OEM-style seat covers for the Ram 1500 are cut for the exact seat shape. They fit the 40/20/40 bench with the fold-down console and are airbag-safe. If you've got the split bench setup, we've got a separate write-up on seat covers for Ram 1500 trucks with 40/20/40 split seats that walks through the fitment quirks. Same product line as our other truck seat covers built for work and off-road use, priced around half of what a dealer reupholstery costs.

Frequently Asked Questions

Q: What is the stock tire size on a 2021 Ram 1500 Big Horn?

The 2021 Big Horn ships with 265/70R17 on 17-inch wheels as the base setup. If your truck came with the 20-inch wheel package, you're running 275/55R20 instead. The Sport Appearance package on the Big Horn also opens up 22-inch wheels with 285/45R22. Check the door jamb sticker to confirm which one you've got, since dealers sometimes mixed packages.

Q: Can I put 35-inch tires on a Ram 1500 without a lift?

Not on a standard suspension setup. A stock Big Horn or Laramie rubs at the upper control arm on full lock and at the rear inner fender on compression. You need at least a 2-inch front level plus mud flap trimming to fit a 35 cleanly. A full 4-inch lift gets you there with zero rubbing. The TRX is the exception. It runs 35s from the factory on a unique widebody suspension that other trims don't share.

Q: What tire size does the Ram 1500 Rebel use from the factory?

The Rebel runs LT275/70R18 Goodyear Wrangler DuraTrac tires. That's a true 33-inch all-terrain on 18-inch wheels. On the upgraded wheel package, those wheels are beadlock-capable, meaning you can run lower air pressures off-road without rolling a bead. The DuraTrac is severe-snow rated and built to handle gravel, rock, and packed dirt without chewing itself up on pavement.

Q: Will changing my Ram 1500 tire size affect the speedometer?

Yes. A taller tire makes the speedometer read low (you're going faster than it shows). A shorter tire makes it read high. Stay within 3% of the factory overall diameter and you don't need to recalibrate. Go bigger than that and you'll want a programmer like a SuperChips or DiabloSport to set the speedo correctly. Otherwise your odometer and transmission shift points drift off.

Q: What is the biggest tire I can fit on a stock Ram 1500 Classic?

The Classic (2019-2024 carryover of the fourth-gen body) handles up to 285/70R17 on stock suspension with no rubbing. That's a 33-inch tire. A few owners report mild flap contact at full lock, easily solved by trimming the front mud flap edge. Add a 2-inch leveling kit and you can step up to 295/70R17 or LT285/75R17 without issues.

Q: Where is the factory tire size listed on my Ram 1500?

Open the driver's door and look at the sticker on the inside edge of the door jamb, near where the latch sits. It lists your factory tire size, recommended cold inflation pressure (front and rear), and the maximum vehicle load. The owner's manual also shows it, but the door sticker is VIN-specific and beats the generic manual chart. You can cross-check on the Ram spec page using your model year.

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